Mouse Look iphone script help

Hi,

I tried creating a script with this

function Update () {
for (var evt : iPhoneTouch in iPhoneInput.touches)
{
if (evt.phase == iPhoneTouchPhase.Moved)
{
look2.SetInput (evt.positionDelta);
}
}
}
But I get an error

NullReferenceException: Object reference not set to an instance of an object
iPhoneAnalogSticks.Update () (at Assets/iPhoneAnalogSticks.js:13)

Can anybody help?

Stupid me I forgot to put main camera as Look2. But now when I touch the screen and drag, the camera keeps on spinning…