iPhone touch screen controls

Hi, I created a FPS game using the Unity FPS tutorial http://unity3d.com/support/resources/tutorials/fpstutorial.html
The game was built in a Mobile unity file “FirstPersonTilt.unity” then transferred to an iPod Touch.
On the iPod touch, tilting the device to the left or right moves the FPS controller in that direction.
Touching the lower left corner of the iPod, moves the FPS controller forwards or backwards.

The controls work as they should. When I touch any part of the screen the machine gun fires.
This includes the lower left corner when I’m moving forwards or backwards.

On the iPod touch, how do I get the lower left corner to move forwards and backwards only,
not having the FPS controller firing the machine gun as its walking.
Is there a script file or setting for this?

Any help is appreciated.
Thank you

There are some tests of varying levels of complication. I would stick to the simplest though. Get the Rect for the Lower left corner (0 , 0 , width, height). Then do a quick test to make sure the tap isn’t in that position before firing:

var leftCorner : Rect = new Rect(0 , 0 , width width , height);
//You could set this value to another rect in a different script using GetComponent.<ScritptName>().variable.

if( !leftCorner.Contains(touch.position) ) {
        //fire your gun here.
}

Hi, I’m fairly new to Unity. I tried the suggested code and got an error message.
Perhaps it’s the way I am applying the code?

I created a JavaScript file in the Project tab, copied and pasted the copied into the script file.
Placed the script file onto “Move TouchPad” in Hierarchy.
Pressed play and got the message "Assets/Rect_controller.js(1,48):BCE0044:expecting),found’width’.

If someone could help me properly apply this script, it would be greatly appreciated.