<!--//
var mymessage = "Sorry, that function is disabled.";

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
//-->