http://www.greatbritishgaming.co.uk/newsitetest.html

Hi, im very new to to all this but am in charge of building a site for my gaming clan. i built out current site and been progressing nicely and learning as i go.
however, on the new version the difference in size between the 2 browsers is way larger than anything ive come accross before.

here is my code

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
<head>


<title>gbt home page</title>


<style type="text/css">

body
{background-color:000000;
margin:auto;
border:1px solid;
border-color:000000;
color:FFFFFF;
font: 10pt Arial,Helvetica,sans-serif;
overflow:auto}



.mpd1{width:1900px;height:100px;top:0;left:0px;position:absolute}

.mpd2{width:500px; height:800px;top:97px;left:0px;position:absolute}

.mpd3{width:500px;height:800px;top:97px;left:1400px;position:absolute}

.hold{background-color:transparent}



</style>

</head>
<body>




<div class="hold"><div class="contain">


<div class="mpd1">

<img src="http://www.greatbritishgaming.co.uk/images/newgbtlogo.jpg"

height="95"width="1895">

</div>



<div class="mpd2">

<img src="http://www.greatbritishgaming.co.uk/images2/leftbg.jpg"

height="795"width="495">

</div>

<div class="mpd3">


<img src="http://www.greatbritishgaming.co.uk/images2/rightbg.jpg"

height="795"width="495">

</div>




</body>
</html>



i cant see what im missing.

please help