().dialog is not a function?

().dialog is not a function?

Hello,

I figure I'm making some simple mistake trying to use the dialog widget, but I can't figure it out. The error message I get is:

$("#dialog_box").dialog is not a function



Here's is the html I'm using:

<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.min.js" type="text/javascript"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.10/jquery-ui.min.js" type="text/javscript"></script>
</head>
<body>

Test 1,2,3....

<div id="dialog_box">Dialog Text Here</div>
<script type="text/javascript">
        $("#dialog_box").dialog();
</script>
</body>
</html>


Any pointers? Thanks.