Displaying GUITexture after all triggers activated

Hello I would like to know how to display a gui texture after more than one trigger has been activated. Such as only after all three triggers were activated a gui texture would be displayed. I have tried the following code but I get errors. Thanks.

 var youwinGUI : GUITexture; 
 var zombie : GameObject;
 
 function OnTriggerEnter(Collider){zombie, activated = true;}
  Bool : a = Gobj1. GetComponent(Trigger).activated;
  Bool : b = Gobj2. GetComponent(Trigger).activated;
  Bool : c = Gobj3. GetComponent(Trigger).activated;
  
 If (a&&b&&c){activated; youwinGUI.enabled = true;}