function centerPopUp( url, name, width, height ) {
		var str = "height=" + height + ",width=" + width;
		if ( window.screen ) {
			var ah = screen.availHeight - 30;
			var aw = screen.availWidth - 10;
	
			var xc = ( aw - width ) / 2;
			var yc = ( ah - height ) / 2;
	
			str += ",left=" + xc + ",screenX=" + xc;
			str += ",top=" + yc + ",screenY=" + yc;
		}
		window.open( url, name, str );
	}