How do i make this script work more then once?

Hello i have this script to when clicked on the screen move camera, but it only works once how can i make it to work all the time?

  #pragma strict
  function Update ()
  {
  if (Input.GetMouseButton(0))
  {
  Camera.main.transform.position = Vector3(51,3,0);
  }

  }

Looks to me like your logic here says to move the camera to the world space coordinates of (51,3,0). Once it is moved there, every button hit after that will again move it to the same location (51,3,0) so it looks like it is just running this one time. Once you are at (51,3,0) it will never look any different no matter how many calls to the code you make. If you want it to increment by 51 and 3, you would use Camera.main.transform.Translate(51,3,0). Make sure that you also multiply this by Time.deltaTime in order to slow it down a bit.