I have problem when i want to using button instead keyboard in iOS

Hi every one I have to try this code of keyboard I need to using GUI Button instead of keyboard See my code ,I already try to use but doesn’t work any more Pls help me.
Cheers!

private var axisH: float = 0;
private var axisV: float = 0;

function InputGetAxis(axis: String): float {

var v = Input.GetAxis(axis);
if (Mathf.Abs(v) > 0.005) return v;
if (axis=="Horizontal") return axisH;
if (axis=="Vertical") return axisV;

}

function OnGUI(){

axisV = axisH = 0;
if (GUI.RepeatButton(Rect(50, 10, 40, 40), "W")) axisV = 1; 
if (GUI.RepeatButton(Rect(50, 90, 40, 40), "S")) axisV = -1; 
if (GUI.RepeatButton(Rect(10, 50, 40, 40), "A")) axisH = -1;
if (GUI.RepeatButton(Rect(90, 50, 40, 40), "D")) axisH = 1;

}

function OnGUI()

{
	if(GUI.RepeatButton(Rect(50,10,40,40),"W"))
	{
		transform.Translate(Vector3.forward*Time.deltaTime*100); 
	}

	if(GUI.RepeatButton(Rect(50,90,40,40),"S"))
	{
		transform.Translate(Vector3.back*Time.deltaTime*100);
	}

	if(GUI.RepeatButton(Rect(10,50,40,40),"A"))
	{
		transform.Translate(Vector3.left*Time.deltaTime*100);
	}

	if(GUI.RepeatButton(Rect(90,50,40,40),"D"))
	{
		transform.Translate(Vector3.right*Time.deltaTime*100);
	}
}