How to make custom loading screen scale?

Hi, I’m currently making a loading screen for my friend’s server, made one in paint, uploaded it to tinypic, and put it in an HTML and uploaded it. It wouldn’t scale though, so I put a scale code that will scale it with window size; you can see here: http://pastehtml.com/view/bnhu9ga9a.html . I put it in a test server I made on my computer (my friend with much better internet than mine hosts it on his machine, and I don’t need to be constantly uploading random crap to his machine :P). and when I joined the server, sure the image was there, but it wouldn’t scale up or down (I tested in every resolution, even 640x480). Any help?

Image size: 1024x767
Main resolutions I play at: 1440x900 and 1680x1050.

THANKS IN ADVANCE!

Edit:
I forgot to include the code I’m using, also, if there isn’t a way to scale it, that’s fine (scaling would still be preferable though), but how could I center it to the middle of the window?



<head>
	<meta http-equiv="content-type" content="text/html; charset=utf-8" />
	<title>test</title>
	<style type="text/css">

	body {
	margin: 0;
	padding: 0;
	}

img {
	width: 100%;
	}
img {
	height: 100%;
	}

	</style>
</head>
<body>
<img src="http://i43.tinypic.com/29w486b.jpg" alt="" />
</body>


Edit 2: Sorry, misorganization on my end, sorry about that! I had +sv_loadingurl “” in my Garry’s Mod server start shortcut target box pointed at an old test URL, I updated everything, now it works!