function openwin(url,winname,w,h,attribs) {
	var l = parseInt((screen.availWidth-w)/2);
	var t = parseInt((screen.availHeight-h)/2);
	attribs = 'width='+w+',height='+h+',left='+l+',top='+t+(attribs!=null ? ','+attribs : '');
	var win = window.open(url, winname, attribs);
	win.focus();
	return false;
}