Collider not found

Collider not found.

     var ShowEnd = false;
     
     function OnGUI() {
         
         if(ShowEnd == true) {
         
             GUI.Box    (Rect(100, 100, 700, 400), "");
         
         }
     }
     
     function OnTiggerEnter( other : Collider) {
     
         if( other.tag == "Door1") {
             
             ShowEnd = true;
         
         }
     
     }

I have the tags and all set up an I did not make it a private var so i can test it I can turn it on and off but the door can not. and i do not know if "Not Found i how i should say it"

but if you guys have any way of telling me what I am doing wrong then plz tell me

      Thanks