function popup(url,name,windowWidth,windowHeight){

	myleft=(screen.width)?(screen.width-windowWidth)/2:100;

	mytop=(screen.height)?(screen.height-windowHeight)/2:100;

	properties = "width="+windowWidth+",height="+windowHeight+",scrollbars=auto, top="+mytop+",left="+myleft;

	window.open(url,name,properties)

}