var mymessage = "Sorry, but you can't view the source of this page.";



if (document.layers){

document.captureEvents(Event.MOUSEDOWN);

}



function rtclickcheck(keyp){



  if (document.layers && keyp.which != 1) {

    alert(mymessage);

    return false;

  }





  if (document.all && event.button != 1) { 

    alert(mymessage);

    return false;

  }

}



document.onmousedown = rtclickcheck