function loader(url) {
		var width = 800;
		var height = 600;
		var center = 1;
	
    xposition=0; yposition=0;
    if ((parseInt(navigator.appVersion) >= 4 ) && (center)){
        xposition = (screen.width - width) / 2;
        yposition = (screen.height - height) / 2;
    }
	
	args = "width=" + width + "," + "height=" + height + "," + "location=0," + "menubar=0," + "resizable=0," + "scrollbars=0," + "status=0," + "titlebar=0," + "toolbar=0," + "hotkeys=0," + "screenx=" + xposition + "," + "screeny=" + yposition + "," + "left=" + xposition + "," + "top=" + yposition + "," + "dependent=0";
	
	window.open(url, "tutorial", args);
	
}