var popUpWin=0;

function popUpWindow(URLStr, left, top, width, height) {
    if(popUpWin) {
        if(!popUpWin.closed)
          popUpWin.close();
    }
	popUpWin = open(URLStr, 'burritos', 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
}