jQuery modal dialog causes error on IE

I have this little snippet, which works on FF, C, O, etc... but I got this error in IE:

Object doesn't support this property or method

What should I do?

<script src="js/pop.js"></script>
<开发者_Go百科;script>
    $(document).ready(function () {


        $("#dialog").dialog({
            height: 140,
            modal: true
        });
    });
</script>

Make the script an explicit type "text/javascript" possibly. But other than that, I don't see anything completely wrong (without knowing what .dialog requires)

EDIT judging by the error message, IE either can't locate the code for .dialog or for jQuery. Which line is the error occurring on? (can you point it out?)