Add Dynamic Values Into Css

if you can add dynamic values into a css. I have an image which i want to set as a backgroung image but depending on who is logged in will depend on what image is being pulled out. I dont want the image to be repeated though out the region it is in so i have used the following syle sheet code. But i have had to adda an actual image name in. Is there any way to make this dynamic image value or not. And if not is there another way i could create a similar effect? Code:

.image
{
background-image:url(images/maps/bangor.gif);
background-position:center;
background-repeat:no-repeat;
}