RTS style camera

I created a script for a camera so i could scroll across the screen for my RTS game. so far i just created a plane and have the camera and attached the script to the camera. When i hit play however, nothing happens and the mouse scrolls all over the screen, not just in the game view. i get no error for my code either. here is my code.

Ummm. Maybe this will help.

private var theScreenWidth : int;
private var theScreenHeight : int;
 
function Start() 
{
    theScreenWidth = Screen.width;
    theScreenHeight = Screen.height;
}
 
function Update() 
{
    if (Input.mousePosition.x > theScreenWidth - Boundary)
    {
       transform.position.x += speed * Time.deltaTime; // move on +X axis
    }
 
    if (Input.mousePosition.x < 0 + Boundary)
    {
       transform.position.x -= speed * Time.deltaTime; // move on -X axis
    }
 
    if (Input.mousePosition.y > theScreenHeight - Boundary)
    {
       transform.position.z += speed * Time.deltaTime; // move on +Z axis
    }
 
    if (Input.mousePosition.y < 0 + Boundary)
    {
       transform.position.z -= speed * Time.deltaTime; // move on -Z axis
    }
 
}   
 
/*function OnGUI() 
{
    GUI.Box( Rect( (Screen.width / 2) - 140, 5, 280, 25 ), "Mouse Position = " + Input.mousePosition );
    GUI.Box( Rect( (Screen.width / 2) - 70, Screen.height - 30, 140, 25 ), "Mouse X = " + Input.mousePosition.x );
    GUI.Box( Rect( 5, (Screen.height / 2) - 12, 140, 25 ), "Mouse Y = " + Input.mousePosition.y );
}*/