onTriggerEnter2D not acting like I thought

Hey, so I was fiddling around with onTriggerEnter2D, and I succesfully wrote a script that tested if a certain collider entered the trigger, and set a static var "collide" equal to true if it did. Here was my original script:

 #pragma strict
 var target : Collider2D; 
 static var collide : boolean;
 
 function OnTriggerEnter2D(collision:Collider2D){
     if(collision == target){
         collide = true;
     }
     else{
         collide = false;
     }
 }
 function Update () {
 }

It worked, and I was able to do stuff only when collide was true in other scripts. However, once the target object left the trigger the collide var was never turned off! This makes sense, of course, since the else - false statement only comes into affect if ANOTHER collider enters the trigger. I decided to make a "called" variable to fix the problem:

 #pragma strict
 var target : Collider2D; 
 static var collide : boolean;
 private var called : boolean;
 
 function OnTriggerEnter2D(collision:Collider2D){
     if(collision == target){
         collide = true;
     }
     else{
         collide = false;
     }
     called = true;
 }
 function Update () {
     if(!called){
         collide = false;
     }
     called = false;
 }

I would naturally thing that this would turn collide off only when there is not a collision with the target. However, when I run the script, my collide script doesn't have any effect. Is there something I'm missing here? Is cross referencing between OnTriggerEnter and Update a bad idea? If so, is there a way to do an if(!OnTriggerEnter) or something of that effect?