On trigger exit not working

I am having trouble with on trigger exit function. When I enter the trigger it works properly, but even if im still in the trigger the OnTriggerExit Function will activate. Please help.

Code:

 var trigger : int = 1;
 var detection : int = 1;
 var Timer : int = 2000;
 
 function Start () {
 
 }
 
 function OnTriggerEnter (other : Collider) {
 detection = 3;
     }
 function OnTriggerExit (other : Collider) {
 detection = 2;
 if(detection == 2)
 {
 yield WaitForSeconds (5);
 Debug.Log("Ware is he?");
 }
     }
     function Update () {
         if(detection == 3)
         {
         if(trigger == 1)
         {
         Debug.Log("Get Him!");
         trigger = 0;
         }
         }
     }