function doPopup (url, width, height, scrollbars) {
	if (typeof scrollbars == "undefined") {
		scrollbars = "1";
	}
	leftPixel = (screen.width / 2) - (width / 2);
	topPixel = (screen.height / 2) - (height / 2);
	height = height + 20;
	width = width + 20;
	var popWin;
	popWin = window.open(url, "pop_win", "width="+width+", height="+height+", scrollbars="+scrollbars+",status=no,left="+leftPixel+",top="+topPixel);
	if (window.focus) {
		popWin.focus();
	}
}