JQuery dialog ::: Type Error: b is undefined

JQuery dialog ::: Type Error: b is undefined

 
<html>
<head>


<script src="/javascript/jquery-1.8.0.min.js"></script>
<script src="/javascript/jquery-ui-1.8.0.min.js"></script>
<link rel="stylesheet" href="jquery-ui.css" />
<script>
jQuery(function() {
jQuery( "#dialog" ).dialog();
    jQuery("#dialog").dialog("open"): 
});
</script>
</head>
<body>
<div id="dialog"></div>
</body>