Endless counting in if statment.

So I have this script

public var ClickTimer : float = 5f;

function Update () {
    var Timer = 0.0f;
    var time = Time.time;

    if (something){}
    else if (Timer <= ClickTimer) {
        Timer += time;
        print(Timer + time); DoubleTap = true;}
    }
    else{
        DoubleTap = false;
    }

}

but it never ends, once Timer = 5; it just keeps going which should make the if statement not true.

Because Timer is initialised inside of the Update Function, it will always have an initial value of 0, ergo it will always run no matter what.
One way to fix this would be by insilyazing Timer outside the Update function (Like you did with ClickTimer). This way it can retain its value in the next frame.

public var ClickTimer : float = 5f;
var Timer = 0.0f;
var DoubleTap = false;

	function Update () {
		var time = Time.deltaTime;
		if (Timer <= ClickTimer) 
		{
			Timer += time;
			DoubleTap = true;
		}
		else 
		{
			DoubleTap = false;
		}
		
		print ("Timer = " + Timer + "

DoubleTap = " + DoubleTap);
}

http://unity3d.com/learn/tutorials/modules/beginner/scripting