var poppedWindow;

function newWindow(url,w,h,noBars) {
	if (poppedWindow) {
		poppedWindow.close();
	}
	var x=(screen.width-w)/2;
	var y=(screen.height-h)/2-60;
	var bars = (noBars) ? 'no' : 'yes';
	var winOptions = 'toolbar=' +bars+ ', location=' +bars+ ', directories=' +bars+ ', status=' +bars+ ', menubar=' +bars;
	winOptions += ', scrollbars=yes, resizable=yes, copyhistory=' +bars+ ', width=' + w + ', height=' + h + ', left=' + x + ', top=' + y;
	poppedWindow = window.open(url,"_blank",winOptions);
	poppedWindow.focus();
	return false;
}