how can i limit rotation on x and y

hi all , please how i can limit the rotation on x and y … i,m still a biggener
this is my code :

 var h : float;
 var v : float;
 var horozontalSpeed : float = 2.0;
 var verticalSpeed : float = 2.0;
 

if (touch.phase == TouchPhase.Moved){

             h = horozontalSpeed * touch.deltaPosition.x ;
             transform.Rotate( 0, h, 0);
             
             v = verticalSpeed * touch.deltaPosition.y ;
             transform.Rotate( v, 0, 0);
         }

I think you are trying ask how to clamp values. Check this function from reference: http://docs.unity3d.com/ScriptReference/Mathf.Clamp.html

Here is how I do it in one of my controller scripts:

	cursorX = Mathf.Clamp (cursorX, minimumX, maximumX);
	cursorY = Mathf.Clamp (cursorY, minimumY, maximumY);

Hope it helps!