the images change but not the size.........why!!!!

[sebs]

here's my code

<script language="javascript">
var ImageList;
var pos=0;
ImageList = new Array();

ImageList[0] = new Image(41,20);
ImageList[0].src = '../images/headers/homes.gif';

ImageList[1] = new Image(41,20);
ImageList[1].src = '../images/headers/over/homes.gif';

ImageList[2] = new Image(37,20);
ImageList[2].src = '../images/headers/decks.gif';

ImageList[3] = new Image(37,20);
ImageList[3].src = '../images/headers/over/decks.gif';

ImageList[4] = new Image(45,20);
ImageList[4].src = '../images/headers/interiors.gif';

ImageList[5] = new Image(45,20);
ImageList[5].src = '../images/headers/over/interiors.gif';

ImageList[6] = new Image(100,20);
ImageList[6].src = '../images/headers/more.gif';

ImageList[7] = new Image(100,20);
ImageList[7].src = '../images/headers/over/more.gif';


function changeIMG(){
if (navigator.appName == 'Netscape'){
	//document.images["thePic"] = new Image(100,100);
	document.images["thePic"].src=ImageList[pos].src;
	document.images["thePic"].width = ImageList[pos].width;
	document.images["thePic"].height= ImageList[pos].height;
}else{
	document.thePic.src=ImageList[pos].src;
	document.thePic.width=ImageList[pos].width;
	document.thePic.height=ImageList[pos].height;
	}
}
</script>

it works in explorer(of course) but netscape gives me trouble:
it takes the size of the default image in the img tag!

if i change image, the images changes but not the size!!

does some1 know how to get around this!!