I need a help to restrict camera movement in game world in x-axis

Can anyone help me out from this problem i need to restrict my camera movement to -180 to 180 degrees in the game world and my code is #pragma strict

@script RequireComponent( GUITexture )

// A simple class for bounding how far the GUITexture will move class Boundary { var min : Vector2 = Vector2.zero; var max : Vector2 = Vector2.zero; }

static private var joysticks : Joystick[]; // A static collection of all joysticks static private var enumeratedJoysticks : boolean = false; static private var tapTimeDelta : float = 0.3; // Time allowed between taps

var touchPad : boolean; // Is this a TouchPad? var touchZone : Rect; var deadZone : Vector2 = Vector2.zero; // Control when position is output var normalize : boolean = false; // Normalize output after the dead-zone? var position : Vector2; // [-1, 1] in x,y var tapCount : int; // Current tap count

private var lastFingerId = -1; // Finger last used for this joystick private var tapTimeWindow : float; // How much time there is left for a tap to occur private var fingerDownPos : Vector2; private var fingerDownTime : float; private var firstDeltaTime : float = 0.5;

private var gui : GUITexture; // Joystick graphic private var defaultRect : Rect; // Default position / extents of the joystick graphic private var guiBoundary : Boundary = Boundary(); // Boundary for joystick graphic private var guiTouchOffset : Vector2; // Offset to apply to touch input private var guiCenter : Vector2; // Center of joystick

function Start() { // Cache this component at startup instead of looking up every frame
gui = GetComponent( GUITexture );

 // Store the default rect for the gui, so we can snap back to it
 defaultRect = gui.pixelInset;    
 
 defaultRect.x += transform.position.x * Screen.width;// + gui.pixelInset.x; // -  Screen.width * 0.5;
 defaultRect.y += transform.position.y * Screen.height;// - Screen.height * 0.5;
 
 transform.position.x = 0.0;
 transform.position.y = 0.0;
     
 if ( touchPad )
 {
     // If a texture has been assigned, then use the rect ferom the gui as our touchZone
     if ( gui.texture )
         touchZone = defaultRect;
 }
 else
 {                
     // This is an offset for touch input to match with the top left
     // corner of the GUI
     guiTouchOffset.x = defaultRect.width * 0.5;
     guiTouchOffset.y = defaultRect.height * 0.5;
     
     // Cache the center of the GUI, since it doesn't change
     guiCenter.x = defaultRect.x + guiTouchOffset.x;
     guiCenter.y = defaultRect.y + guiTouchOffset.y;
     
     // Let's build the GUI boundary, so we can clamp joystick movement
     guiBoundary.min.x = defaultRect.x - guiTouchOffset.x;
     guiBoundary.max.x = defaultRect.x + guiTouchOffset.x;
     guiBoundary.min.y = defaultRect.y - guiTouchOffset.y;
     guiBoundary.max.y = defaultRect.y + guiTouchOffset.y;
 }

}

function Disable() { gameObject.active = false; enumeratedJoysticks = false; }

function ResetJoystick() { // Release the finger control and set the joystick back to the default position gui.pixelInset = defaultRect; lastFingerId = -1; position = Vector2.zero; fingerDownPos = Vector2.zero;

 if ( touchPad )
     gui.color.a = 0.025;    

}

function IsFingerDown() : boolean { return (lastFingerId != -1); }

function LatchedFinger( fingerId : int ) { // If another joystick has latched this finger, then we must release it if ( lastFingerId == fingerId ) ResetJoystick(); }

function Update() {
if ( !enumeratedJoysticks ) { // Collect all joysticks in the game, so we can relay finger latching messages joysticks = FindObjectsOfType( Joystick ) as Joystick[]; enumeratedJoysticks = true; }

 var count = Input.touchCount;
 
 // Adjust the tap time window while it still available
 if ( tapTimeWindow > 0 )
     tapTimeWindow -= Time.deltaTime;
 else
     tapCount = 0;
 
 if ( count == 0 )
     ResetJoystick();
 else
 {
     for(var i : int = 0;i < count; i++)
     {
         var touch : Touch = Input.GetTouch(i);            
         var guiTouchPos : Vector2 = touch.position - guiTouchOffset;
 
         var shouldLatchFinger = false;
         if ( touchPad )
         {                
             if ( touchZone.Contains( touch.position ) )
                 shouldLatchFinger = true;
         }
         else if ( gui.HitTest( touch.position ) )
         {
             shouldLatchFinger = true;
         }        
 
         // Latch the finger if this is a new touch
         if ( shouldLatchFinger && ( lastFingerId == -1 || lastFingerId != touch.fingerId ) )
         {
             
             if ( touchPad )
             {
                 gui.color.a = 0.15;
                 
                 lastFingerId = touch.fingerId;
                 fingerDownPos = touch.position;
                 fingerDownTime = Time.time;
             }
             
             lastFingerId = touch.fingerId;
             
             // Accumulate taps if it is within the time window
             if ( tapTimeWindow > 0 )
                 tapCount++;
             else
             {
                 tapCount = 1;
                 tapTimeWindow = tapTimeDelta;
             }
                                         
             // Tell other joysticks we've latched this finger
             for ( var j : Joystick in joysticks )
             {
                 if ( j != this )
                     j.LatchedFinger( touch.fingerId );
             }                        
         }                
 
         if ( lastFingerId == touch.fingerId )
         {    
             // Override the tap count with what the iPhone SDK reports if it is greater
             // This is a workaround, since the iPhone SDK does not currently track taps
             // for multiple touches
             if ( touch.tapCount > tapCount )
                 tapCount = touch.tapCount;
             
             if ( touchPad )
             {    
                 // For a touchpad, let's just set the position directly based on distance from initial touchdown
                 position.x = Mathf.Clamp( ( touch.position.x - fingerDownPos.x ) / ( touchZone.width / 2 ), -1, 1 );
                 //position.y = Mathf.Clamp( ( touch.position.y - fingerDownPos.y ) / ( touchZone.height / 2 ), -1, 1 );
             }
             else
             {                    
                 // Change the location of the joystick graphic to match where the touch is
                 gui.pixelInset.x =  Mathf.Clamp( guiTouchPos.x, guiBoundary.min.x, guiBoundary.max.x );
                 //gui.pixelInset.y =  Mathf.Clamp( guiTouchPos.y, guiBoundary.min.y, guiBoundary.max.y );        
             }
             
             if ( touch.phase == TouchPhase.Ended || touch.phase == TouchPhase.Canceled )
                 ResetJoystick();                    
         }            
     }
 }
 
 if ( !touchPad )
 {
     // Get a value between -1 and 1 based on the joystick graphic location
     position.x = ( gui.pixelInset.x + guiTouchOffset.x - guiCenter.x ) / guiTouchOffset.x;
     position.y = ( gui.pixelInset.y + guiTouchOffset.y - guiCenter.y ) / guiTouchOffset.y;
 }
 
 // Adjust for dead zone    
 var absoluteX = Mathf.Abs( position.x );
 var absoluteY = Mathf.Abs( position.y );
 
 if ( absoluteX < deadZone.x )
 {
     // Report the joystick as being at the center if it is within the dead zone
     position.x = 0;
 }
 else if ( normalize )
 {
     // Rescale the output after taking the dead zone into account
     position.x = Mathf.Sign( position.x ) * ( absoluteX - deadZone.x ) / ( 1 - deadZone.x );
 }
     
 if ( absoluteY < deadZone.y )
 {
     // Report the joystick as being at the center if it is within the dead zone
     position.y = 0;
 }
 else if ( normalize )
 {
     // Rescale the output after taking the dead zone into account
     position.y = Mathf.Sign( position.y ) * ( absoluteY - deadZone.y ) / ( 1 - deadZone.y );
 }

}