function popup(URL, nHeight, nWidth) {

	if ((nHeight==undefined)||nHeight!=parseInt(nHeight)||nHeight<=0) nHeight=500;
	if ((nWidth==undefined)||nWidth!=parseInt(nWidth)||nWidth<=0) nWidth=400;

	popupWin = window.open(URL, 'popupWin', "toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=no,copyhistory=no,width="+nWidth+",height="+nHeight);
	popupWin.focus();

}