Two Times Button - Looping

Hello!

I have a small problem with looping the if/else function.

I need to turn off/on the lights in my game, while pressing the Middle Mouse Button. So I created animation for my lights and simply play it with normal speed, when the lights are off, and with inverse speed, when they're turning on.

I wrote a small code for twice pressing the Middle Mouse Button (the example of twice pressing code I found on this site), but everything works ONLY ONCE. I press the button - the lights are turned off, press it again - they are turned on. Press again - and nothing going on! So I think, maybe it is possible to loop the function?

Please, help me and sorry for my English.)

Here's the code:

 var LampsOn = 0;

 for (var state : AnimationState in animation) 
 
 {
     state.speed = 0.0;
 }
 
 function Update() {
 
        if (LampsOn == 0 && Input.GetMouseButtonDown(2))
 {

 for (var state : AnimationState in animation) 
 
 {
     state.speed = 1.0;
 };
     LampsOn = 1;
 }

 else if (LampsOn == 1 && Input.GetMouseButtonDown(2))
 {
 for (var state : AnimationState in animation) 
 {
     state.speed = -2.0; 
 };
     LampsOn = 0;
     }

}