[jQuery] xpath not returning objects

[Old Orange Juice]

I have a bunch of divs with the same classname, 'mediafield':

<div id="articles" class="mediafield">Slug:</div><br>
<div id="video" class="mediafield">Big Blurb(Video)<br></div>
<div id="content_short" class="mediafield">Big Blub(short content)
<br></div>
<div id="audio" class="mediafield">Big Blub(Audio)<br></div>
<div id="images" class="mediafield">Photo Uri(images):<br></div>

and I have this jquery code in my header:
<script>
$(document).ready(function() {
                $("input:checkb...@name=media_type]").click(function() {
                        if (this.checked == true) {
                                alert('checkbox true');
                                $("d...@class=mediafield]").hide('fast');

                });
});
</script>

So I know that the click function is getting implemented.. The alert
box appears however I get the following error in firebug:
uncaught exception: Syntax error, unrecognized expression:
[...@class=mediafield]

Line 0

Nothing happens when firebug is turned off... So I'm not sure why it's
throwing the error.

Any help?

Thanks,
ooj