I try to fit a "javacript slide show to screen" but the images doubles to screen!

Can't stretch background image to screen! javascript problem?
in css the width and the height of the div that contains the javascript is at 100% but the image dosen't fit to screen... the image doubles to screen

here the result of this: http://www.3www.gr/test

here is my code....

<div id="wrapper">
<div id="back-ground"></div>


<script language="javascript">
var speed = 4000
var Slide = new Array()

Slide[0] = 'url(image/1.jpg)';

Slide[1] = 'url(image/2.jpg)';

Slide[2] = 'url(image/3.jpg)';


var t
var j = 0
var l = Slide.length
var p = Slide.length

var preLoad = new Array()
for (i = 0; i < l; i++)
{
preLoad[i] = new Image()
preLoad[i].src = Slide[i]
}
</script>
<script language="javascript">runSlideShow();</s…


</div>