fadeto() not working?

fadeto() not working?

hey, I am not very experienced with query which is why i am asking for some help.  i am creating my portfolio website and i want to use jquery to fade out thumbnails.
I have categories of projects in a <ul> Print, Web, Illustration, Photography and when u click on one list item, i want it to fade out all the thumbnails that aren't print (for example), so only the print related projects are full opacity. Here is my code.

<script>
$(document).ready(function() {
$(#printbutton).click(function () {
$(.photo .illus .web).fadeTo("slow", 0.33);
});
});
</script>

<div id="leftmenu">
<ul>
<li>Projects</li>
<span class="class1">
<li><div class="tinyline"></div></li>
<li><a href="#" id="printbutton">Print</a></li>
<span class="class2">
<li><a href="web.html">Web</a></li>
<span class="class3">
<li><a href="illustration.html">Illustration</a></li>
<span class="class4">
<li><a href="photography.html">Photography</a></li>
</ul>
</div>

//Examples of thumbnails.
<div class="thumbbox" class="illus">
<img src="stairsthumb.jpg">
<div class="thumbinfo">
<ul class="infolist">
<li>Rearranging Structures</li>
<li>Photographic Collage.</li>
</ul>
</div>
</div>


<div class="thumbbox" class="print">
<img src="walkmanthumb.jpg">
<div class="thumbinfo">
<ul class="infolist">
<li>The brief guide to the Walkman</li>
<li>Field Guide Design</li>
</ul>
</div>
</div>

<div class="thumbbox" >
<img src="photographythumb.jpg" id="photo">
<div class="thumbinfo">
<ul class="infolist">
<li>Abandoned Asylum, Epsom</li>
<li>Photograph</li>
</ul>
</div>
</div>

Hope someone can help
would really appreciate it
thankyou
craig