Text disappear on OnTriggerExit()

Hi wondering if anyone can help, I have this script placed on a Game Object, when my FPScontrolled which is set to "is Trigger" collids with the gameObject the text appears "Door is locked" but when I walk out of the area the text does not disappear anyone know where im going wrong? thank you

 var ShowGUI : boolean;
 
 function OnTriggerEnter(info : Collider)
 {
     ShowGUI = true;
 }
 
 
 
 function OnGUI()
 {
     if(ShowGUI == true)
         GUI.Label(Rect(400,300,100,20), "Door is Locked");
 }
 function onTriggerExit(info : Collider)
 {
     ShowGUI = false;
 }