Opacity effect not working in IE

Hello everyone.

I´m building a folio gallery and reading the article http://www.w3schools.com/Css/css_image_transparency.asp I decided to apply an oppacity effect on the squares but the problem is that, but as per usual, it is not working on IE.

My gallery is: http://www.laertjansen.com/version02/

I put the code inside a div…like this…could that be the problem? The article only talks about attaching the code to <img>…

<div class=“project” border=“0” style=“opacity:0.5;filter:alpha(opacity=50)” onmouseover=“this.style.opacity=1;this.filters.alpha.opacity=100” onmouseout=“this.style.opacity=0.5;this.filters.alpha.opacity=50”><a href=“works/itcameoutofthesky.jpg” rel=“lightbox[all]” title=“Personal concept and illustration. I call it ‘It came out of the sky’ - October 2008”><img src=“thumbs/it_cameoutof_thesky.jpg”/></a></div>

Thanks a lot in advance for any sort of help.