Logo images Part 2…

I’ve created a div in my theme’s header to hold a logo image.

I’ve styled it:
.mylogo{
width:350px;
height:150px;
margin-top:0px;
margin-left:0px;
background-image: url(‘/wp-content/blogs.dir/2/files/mylogo.jpg’);
background-repeat:no-repeat;
}

This means that a user can upload their own logo image with the wp media libray, and as long as their image is named “mylogo.jpg” then it will show in their header.

The question is – how to avoid me having to edit the url address for every site as each new site appears to get its own blogs.dir folder?