GUI.Toggle to only send one action, not repeated

Hi people,

I've set up a script with a number of toggle buttons. I have them switching on and off when clicked which is fine. When clicked, a function is performed, but it keeps sending the message. What I want to do is just send a single message/action once. This is obviously a standard button action, but I couldn't figure out how a button could have an on/off state; change graphic when touched.

Here's my code:

 #pragma strict
 
 var LeftNavSkin: GUISkin;
 //var toggle = true;
 
 var bt1 = false;
 var bt2 = false;
 var bt3 = false;
  
 // Clears everybody and returns true to help setting the desired one
 function setMeOnly():boolean{
  
   bt1 = bt2 = bt3 = false;
   return true;
 }
  
 function OnGUI () {
  
   GUI.skin = LeftNavSkin;
   
   GUI.Box (Rect (-30,10,100,90), "");
  
   //Top Left Button
   if (GUI.Toggle (Rect(50,300,100,100), bt1, "")) bt1 = setMeOnly();
   
  
   //Middle Button
   if (GUI.Toggle (Rect(50,410,100,100), bt2, "")) bt2 = setMeOnly();
  
   //Bottom Right Button
   if (GUI.Toggle (Rect(50,520,100,100), bt3, "")) bt3 = setMeOnly();
         
 //This sends the debug.log repeatedly. I want it to just send once.
 
 if(bt1 === true)
 {
    Debug.Log("OMG IT WORKS");
 }
 
 }

Help would be appreciated!

Rich