make a page out of the above code(say quickbox.aspx) and then make use html onload method call the javascript to open the page(quixkbox.aspx)
<script language="JavaScript">
function display()
{
var URL = "./quickbox.aspx";
var Name = "popup";
var Fensteroptionen = "toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=0";
var Breite = 800;
var Hoehe = 600;
window.open(URL, 'Name', Fensteroptionen + ',width=' + Breite + ',height=' + Hoehe);
}
</script>
</head>
<body onload=display();>