function pop_drag_trigger (pPtr, event) {
  //alert ('drag_trigger');
         pPtr.style.cursor = "move";
         var clicked = document.createElement ('input');
         clicked.type = 'hidden';
         clicked.id = 'clicked';
         clicked.value = '1';
         document.body.appendChild (clicked);
}

function pop_nodrag (pPtr, event) {
         //alert ("event.clientX := " + String (event.clientX) + "\tevent.clientY := " + String (event.clientY) + "\nevent.screenX := " + String (event.screenX) + "\tevent.screenY := " + String (event.screenY));
         var clicked = document.getElementById ('clicked');
         if (clicked) {
            pPtr.style.left = String (event.clientX) + "px";
            pPtr.style.top = String (event.clientY) + "px";
         }
         
         pPtr.style.cursor = "default";
         document.body.removeChild (document.getElementById ('clicked'));
}