diff --git a/ch04/Exercise.java b/ch04/Exercise.java
index ba8c2a9..7e7234d 100644
--- a/ch04/Exercise.java
+++ b/ch04/Exercise.java
@@ -1,25 +1,56 @@
 public class Exercise {
-
+    
+    
+    /**
+     * when zoop() invoked, calls baffle()
+     * and then prints "You Wugga "
+     * and calls baffle() again. 
+     */
     public static void zoop() {
         baffle();
         System.out.print("You wugga ");
         baffle();
     }
-
+    
+    /**
+     * @param args
+     * prints "No, I "
+     * calls zoop()
+     * prints "I "
+     * then calls baffle()
+     */
     public static void main(String[] args) {
         System.out.print("No, I ");
         zoop();
         System.out.print("I ");
         baffle();
+        zool(11, "Mishu", "Sand Hollow");
     }
-
+    
+    /**
+     * When baffle() is invoked, prints "wug"
+     * and calls ping()
+     */
     public static void baffle() {
         System.out.print("wug");
         ping();
     }
-
+    
+    /**
+     * When ping() is invoked, prints "."
+     */
     public static void ping() {
         System.out.println(".");
     }
+    
+    /**
+     *
+     * @param age
+     * @param pet
+     * @param street
+     */
+    public static void zool(int age, String pet, String street) {
+        System.out.print ("\n" + age + pet + street);
+    }
 
 }