[How to] add Javascript to CSS

[gamerfu]

I want my images to rotate, but cannot quite figure out the CSS function.

I have this:
.headerL {
height: 180px;
float: left;
width: 309px;
background-image: url(images/styles/1ATKSUM/misc/logo/left/0004.png);
background-repeat: no-repeat;
}


but want this:
.headerL {
height: 180px;
float: left;
width: 309px;
background-image: url(<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
showLeftImage();
// End --></script>);
background-repeat: no-repeat;
}


Ideas? :cool: