Unity2D: Renderer off/ on by triggers

Basically, I have a sprite which resembles a torch. If the torch is over the trap on the floor then it will turn on the renderer however when I move the torch off the trap, the traps renderer is still on and should turn off. Can anyone help me with this?

 #pragma strict
 
 private var CanShow : boolean = false;
 
 
 function Update()
 {
     if(CanShow)
     {
         this.GetComponent(Renderer).enabled = true;
     }
     if(!CanShow)
     {
         this.GetComponent(Renderer).enabled = false;
     }
 }
 
 
 function OnTriggerEnter2D(other : Collider2D)
 {
     if(other.tag == "Torch")
     {
         CanShow = true;
     }
 }
 function OnTriggerExit2D(other : Collider2D)
 {
     if(other.tag == "Torch")
     {
         CanShow = false;
     }
 }