function popUpSimple( URL, width, height ){
     if (!height) height=650;
     var popwin = popUp( URL, width, height, "status=no,location=no,menubar=no,toolbar=no,directories=no,resizable=yes,scrollbars=yes");    
   }
   function popUnder( URL, width, height ){
     popup_window = popUp( URL, width, height );
     popup_window.blur();
   }

   function popUnderNoResize( URL, width, height ){
     var popup_window = popUpNoResize( URL, width, height );
     popup_window.blur();
   }
   
   function popUp( URL, width, height, props ){
       if (!props) props = "status=yes,location=yes,menubar=yes,toolbar=yes,directories=no,resizable=yes,scrollbars=yes";
       if (!width) width=800;
       if (!height) height=500;
       var popup_window=window.open( URL, "_blank", props + ",width=" + width + ",height=" + height + ",left=50,top=10");
       window.onerror = null;
       return popup_window;
   }