Strange iOS input error..

Whenever I try this bit of code (it is designed to only detect input on the left side of the screen), I get the following error…why? It doesn’t break the game and the works correctly, so what is wrong? Thanks

function Testing(){
	if(Input.touches[0].position.x < Screen.width/2)

IndexOutOfRangeException: Array index
is out of range.

It looks like you are running the if statement every frame, even when there is no touch. Since there is no touch there is nothing occupying the touches array and thus touches[0] is out of range. You should first check that there is a touch before you get the position of a touch.