Xml and Css problem

Question

Hello! I want to add some image to my xml/css document. I have in my xml file line like this:

<screen image="http://www.gram.pl/upl/news/120081127090543.jpg"/&gt;

and in css:

screen:after{
    background-image:url( attr(image) );
    display:list-item;
    width:20px;
    height:30px
}

And I can't see any image :/