function mypopup(url, name, windowWidth, windowHeight, verticalscrollbar)
{
	var myleft=(screen.width)?(screen.width-windowWidth)/2:100;
	var mytop=(screen.height)?(screen.height-windowHeight)/2:100;
	var properties = "width="+windowWidth+",height="+windowHeight+",scrollbars=" + (verticalscrollbar == true ? "yes" : "no") + ",top="+mytop+",left="+myleft;

	window.open(url, name, properties)
}