SWING BASE FOR A CHILD RESTRAINT CROSS-R.EFERENCE TO RELATED APPLICATIONS The present application claims priority from Australian Provisional Patent 5 Application No. 2009905664 filed on 19 November 2009 the contents of which are incorporated herein by reference. FIELD OF INVENTION This invention relates generally to a child safety seat for a vehicle, and in particular, to a base of a child safety seat that enables the seat to be converted for i use in a variety of positions on the seat of the vehicle. BACKGROUND ART The use of child safety seats to accommodate infants and young children whilst travelling in a vehicle is common throughout the world. Most countries have established various laws and regulations that dictate the manner in which infants 15 and children are to be transported in vehicles, and the types of restraints that are acceptable. Most such laws require the infant/child to be restrained in a dedicated and approved child safety seat that is anchored or otherwise secured to a rear seat of the vehicle. The child safety seat may include a dedicated harness that restrains the child in position within the seat, or the child safety seat may 20 utilise the vehicle seat belt or a separate harness to restrain the child therein, depending upon the size and/or age of the child. As such, there exist a variety of types of child safety seats that are approved for use with children of a variety of ages and/or sizes. These types can be broadly characterised as follows. Type A seats typically refer to rear facing seats or 25 capsules suitable for accommodating babies/infants up to around 6 months of age and/or 70 cm in length and up to 12 kg. Type B seats typically refer to forward facing seats used to accommodate toddlers and young children from approximately 6 months to 4 years, or from 8 - 18 kg. Type E seats typically refer to booster seats and booster cushions used to accommodate children 30 between 4 - 8 years old, or approximately from 14 - 32 kg, and which are typically used in combination with the vehicle seat belt. To provide a child safety seat that accommodates a child as they grow, combination child safety seats have been proposed, such as type A/B or type B/E seats. In the case of Type A/B seats, such seats are configured so as to be used as both a rearward facing seat and a forward facing seat to accommodate children up to 4 years, or from infancy to 18 kg. In relation to type B/E combination seats, such seats are configured to be used in a forward facing mode to accommodate a 5 children from as young as 6 months to 8 years old, or from 8 - 32 kg. Hence, whilst some such combination safety seats have been developed for use between different age and weight brackets, during the life of a child there is still a requirement to purchase at least two different types of seats to accommodate transition between a Type A and a Type E seating arrangement. 1o Such combination Type A/B seats and/or Type B/E seats typically provide a base that is configured to be located on the seat of the vehicle. The seat portion of the child safety seat is typically mounted to the base. In a combination Type A/B seat the seat portion is mounted to the base in a manner such that it can be rotated between a rearward and a forward facing position. In the case of a Type B/E seat 15 the seat portion is mounted to the base in a manner than enables the seat portion to be reclinable with respect to the base. Typically, in existing child safety seating arrangements the base is configured to provide a substantially level surface for supporting the child safety seat on the vehicle seat. For most Type A/B seats the base may also include a retractable bar or the like that projects from 20 an undersurface thereof to elevate an edge of the base when used in the rearward facing mode. Such a bar must be activated and locked in position and thus may be incorrectly installed in some instances, resulting in the seat being unstable and the safety of the child being positioned within the seat being compromised. As such, there is a need to provide a child safety seat that can be intuitively 25 adapted for use between a rearward facing mode and a forward facing mode. The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the above prior art discussion does not relate to what is commonly or well known by the person 30 skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part. STATEMENT OF INVENTION Accordingly, in one aspect of the invention there is provided a base for 35 supporting a child safety seat on a vehicle seat comprising: a first foot member for supporting the child safety seat on a surface of the vehicle seat; a second foot member for supporting the child safety seat on a surface of the vehicle seat; and 5 a swing member pivotally connected to the base between the first foot member and the second foot member; wherein, the first foot member is inclined with respect to the second foot member and the swing member is pivotable between a first position wherein the child safety seat is supported on the surface of the vehicle seat 10 by the swing member and the second foot member and a second position wherein the child safety seat is supported on the surface of the vehicle seat by the swing member and the first foot member. In one embodiment, both the first foot member and the second foot member have an undersurface that is substantially planar so as to be received on the surface of 15 the vehicle seat. The inclination of the first foot member to the second foot member is sufficient such that when the undersurface of the first foot member or the second foot member is received on the surface of the vehicle seat, the undersurface of the corresponding second foot member or first foot member is located remote from the surface of the seat. 20 The swing member may have a substantially wedge shape having a thickness greatest at a distal and which tapers towards a proximal end. The swing member may be mounted to the base by way of an axle that passes through the proximal end. The axle may facilitate pivotal movement of the swing member between the first and second position. 25 In one form, when the swing member is in the First position the child safety seat may be configured to be used in a rearward facing mode. In another form, when the swing member is in the second position, the child safety seat may be configured to be used in a forward facing mode. In another aspect, the invention provides a child safety seat for a vehicle 30 comprising: a body for receiving a child therein; and a base configured to support the body on a surface of a seat of the vehicle, the base having; a first foot member for supporting the child safety seat on a surface of the vehicle seat; a second foot member for supporting the child safety seat on a surface of the vehicle seat; and 5 a swing member pivotally connected to the base between the first foot member and the second foot member; wherein, the first foot member is inclined with respect to the second foot member and the swing member is pivotable between a first position wherein the child safety seat is supported on the surface of 10 the vehicle seat by the swing member and the second foot member and a second position wherein the child safety seat is supported on the surface of the vehicle seat by the swing member and the first foot member. In yet another aspect, the invention provides a child safety seat for use in either a 15 front facing mode or a rear facing mode in a vehicle, comprising: a body portion configured to receive a child therein; and a base portion configured to support the body portion on a surface of a seat of the vehicle; wherein the base portion comprises a centrally mounted swing member 20 that is pivotally movable between a first position where the child safety seat is suitable for use in a forward facing manner, and a second portion where the child safety seat is suitable for use in a rearward facing manner. The body portion may be movably mounted to the base portion to facilitate adjustment of an angle of the body portion with respect to the base portion. The 25 swing member may be in the form of a wedge shaped member pivotally mounted on a shaft for movement between the first position and the second position. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be better understood from the following non-limiting description of preferred embodiments, in which: 30 Figure 1 is front perspective view of an embodiment of a child safety seat of the present invention used in a rearward facing mode; Figure 2 is a front perspective view of a child safety seat according to an embodiment of the present invention used in a forward facing mode; Figure 3 is a perspective view of an underside of a base of the child safety seat according to Figure 1 or Figure 2; 5 Figure 4 is a side view of an embodiment of a child safety seat of the present invention when used in a rearward facing mode Figure 5 is a side view of an embodiment of a child safety seat of the present invention when used in a reclined forward facing mode; and Figure 6 is a side view of an embodiment of a child safety seat of the 10 present invention when used in an upright forward facing mode. DETAILED DESCRIPTION OF THE DRAWINGS Preferred features of the present invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings are not to be 1s construed as limiting on the scope of the invention. The present invention will be described below in relation to a child safety seat 10 that is positioned, in use, on a rear seat 5 of a vehicle. For clarity reasons, the manner in which the child safety seat 10 is anchored in position on the rear seat 5 of the vehicle will not be shown. Further, the vehicle seat 5 will be shown in a 20 simplified manner for clarity. However, it will be appreciated that the child safety seat 10 may employ tethers and the like to secure the seat 10 to a dedicated vehicle anchorage point where required, and may also cooperate with the vehicle seat belt system. Such arrangements are well known in the art and will not be described in further detail below. 25 Referring to Figure 1, a child safety seat 10 is shown in a rearward facing or Type A mode of use. The child safety seat 10 typically comprises a body 12 mounted on a base 16. The base 16 is positioned on a surface of the rear seat 5 of the vehicle such that the body 12 is supported in a reclined and rearward facing position. 30 The body 12 comprises a seat portion 13 that supports the child's legs and posterior region, and a backrest portion 14 that supports the child's back, neck and head region. The seat portion 13 and the backrest portion 14 are typically integrally formed by way of injection or blow moulding with a cover having padding and the like positioned thereover to provide comfort to the child. An internal harness (not shown) may be provided to secure the child within the seat 10 and a pair of side wings 15 extends along opposing sides of the seat 10 to further enclose the child and offer protective support to the child. A head rest 5 (not shown) may also be attached to the body 12 adjacent an upper region of the backrest portion 14 to provide support and comfort to the infant's head and neck region. The body 12 is movably mounted to the base 16 to enable adjustment of the reclination of the body 12 with respect to the base 16. In this regard, an upper 10 surface of the base 16 may have a slotted track (not shown) formed therein that receives a corresponding projection provided in an undersurface of the body 12. A locking member (not shown) may be provided to enable the degree of reclination of the body 12 with respect to the base 16 to be locked in position, depending upon whether the seat 10 is to be used in a Type B or Type E mode. It 1s will be appreciated that various arrangements currently exist where bodies of child seats are adjustably reclinable, and such an arrangement will not be described in further detail. The base 16 comprises a first foot portion 17 and a second foot portion 18. The first foot portion 17 and the second foot portion 18 are formed integral with the 20 base 16 and are located on opposing sides of the base 16. In this regard, when the seat 10 is positioned in a rearward facing mode, as shown in Figure 1, the first foot portion 17 is located adjacent the rear of the vehicle seat 5 with the second foot portion 18 being located adjacent the front edge of the vehicle seat 5. Referring to Figure 2, the seat 10 is shown in a forward facing or Type B or Type 25 E mode of use. In this arrangement, the first foot portion 17 is located adjacent the front edge of the vehicle seat 5 with the second foot portion 18 being located adjacent the rear of the vehicle seat 5. The first foot portion 17 and the second foot portion 18 together define a surface that is able to be received on the surface of the vehicle seat 5. The first foot 30 portion 17 and second foot portion 18 are angled with respect to each other such that when one of the first foot portion 17 or second foot portion 18 is located on a surface of the vehicle seat 5, the other of the first foot portion 17 or second foot portion 18 is elevated above the surface of the seat 5. In this regard, only one of the first foot portion 17 or second foot portion 18 substantially supports the seat 35 10 at any one time. As can be seen from the modes of use shown in Figures 1 and 2, when the seat 10 is to be used in a rearward facing mode the second foot portion 18 substantially supports the seat 10 in position on the vehicle seat 5, whilst when the seat 10 is being used in a forward facing mode the first foot portion acts to substantially support the seat 10 in position on the vehicle seat 5. Referring to Figure 3, an underside view of the base 16 of the seat is shown. As can be seen the first foot portion 17 and the second foot portion 18 each extend 5 across the width of the seat 10 along a front and rear edge of the base 16. A swing member 20 is mounted between the first foot portion 17 and the second foot portion 18 by way of an axle 21. The swing member 20 is able to pivot between a first position where it is located opposite the first foot portion 17, as is shown in Figure 3, and a second position where it is located opposite the second 10 foot portion 18. The swing member 20 has a wedged shape that is thicker at a distal end 22 and tapers towards a proximal end 23 through which the axle 21 passes. The shape of the swing member 20 is predetermined such that when the swing member 20 is in the first position or the second position, the swing member 20 acts in association 15 with the first foot portion 17 or second foot portion 18 to support the seat 10 on the surface of the vehicle seat 5. In this regard, the thickness and tapered nature of the swing member 20 enables the seat 10 to be used in a forward facing mode and a rearward facing mode in a stable manner upon the surface of the vehicle seat 5. The swing member 20 may be spring loaded or otherwise biased into a 20 desired position and may be lockable in said position in use. Referring to Figure 4, the manner in which the swing member 20 is employed in a child safety seat 10 in a rearward facing mode can be seen. The body 12 of the seat 10 may be reclined with respect to the base 16 to receive the child. The swing member 20 is then positioned such that it is opposed to the second foot 25 portion 18. This arrangement provides a stable underside of the base 16 to support the seat 10 in position on the vehicle seat 5, and provides a tilt or degree of reclination for using the child safety seat 10 in a rearward facing manner without the need for installing or activating any additional componentry. Referring to Figure 5, the child safety seat 10 is shown in a typical Type B seat 30 position. In this arrangement the seat portion 13 is reclined with respect to the base 16 such that the backrest portion of the seat 10 is angled with respect to the vehicle seat 5 as shown. In this position the swing member 20 is positioned such that it is opposite the first foot portion 17. This arrangement provides a stable underside of the base 16 to support the seat 10 in position on the vehicle seat 5. 35 In Figure 6, the child safety seat 10 is shown in an upright forward facing mode with the backrest portion of the seat 10 substantially parallel with the backrest of the vehicle seat 5, in a traditional Type E or booster seat position. In this arrangement the swing member 20 is also positioned such that it is opposite the first foot portion 17. This arrangement also provides a stable underside of the base 16 to support the seat 10 in position on the vehicle seat 5. 5 It will be appreciated that the configuration of the base 16 of the child safety seat 10 of the present invention enables the seat to be readily converted between a forward facing and a rearward facing mode to suit the changing needs of a child. Due to the swing member 20 and the provision of the first foot portion and the second foot portion, the body 12 of the seat 10 does not require rotation to be 10 used in a rearward or forward facing manner, T his provides a more simple and intuitive seat arrangement for use by parents and the like, without having to activate various components to adapt the seat for use in different modes. Thus, the child safety seat of the present invention is able to be used with the child from infancy until such time as the child no longer requires a safety seat. 15 It will be appreciated that the child safety seat of the present invention comprises an adjustable base having a swing member attached thereto that can be moved between a first position and a second position to adjust the mode of use and the angle of inclination of the child safety seat without requiring rotation of the seat portion of the child safety seat. 20 Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other 25 components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise. Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or 30 instrument will usually be considered in a particular orientation, typically with the seat uppermost. It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.