allora ecco quanto segue:

/* html */
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Documento senza titolo</title>
<style type="text/css">
@import url('musicdj.css');
</style>
</head>

<body>
<div id="container">
<div id="header1">
[img]risingdjinaction.jpg[/img]
</div>
</div>
</body>
</html>

/* musicdj.css */
body {
background-color:#000000;
}

div#container {
background-color:#FFFFFF;
width:750px;
margin:0 auto;
padding:5px 0 0 0;
border-color: #333333;
border-width: 5px;
border-style: ridge;
}

div#header1 {
height:300px;
background-color:#000000;
width:auto;
margin:0 5px;
padding:0;
border-color: #333333;
border-width: 5px;
border-style: ridge;
}

div#header1 img{
display: block;
margin:auto;
padding:0;
border:0;
}