function windowopen(url, name, width, height) {
	var x = (screen.width - width) / 2;
	var y = (screen.height - height) / 2;
	if (url.indexOf("http") == 0) {
		var win = window.open(url, name, "width=" + width + ",height=" + height + ",left=" + x + ",screenX=" + x + ",top=" + y + ",screenY=" + y + ",scrollbars=yes,resizable=yes");
		if (window.focus) {
			win.focus();
		}
		return win;
	} else {
		var win;
		if (url.charAt(0) == '/') {
			win = window.open("http://" + document.location.host + url, name, "width=" + width + ",height=" + height + ",left=" + x + ",screenX=" + x + ",top=" + y + ",screenY=" + y + ",scrollbars=yes,resizable=yes");
		}
      else {
   		win = window.open("http://" + document.location.host + "<%=request.getContextPath()%>/" + url, name, "width=" + width + ",height=" + height + ",left=" + x + ",screenX=" + x + ",top=" + y + ",screenY=" + y + ",scrollbars=yes,resizable=yes");
      }
		if (window.focus) {
			win.focus();
		}
		return win;
	}
}