Untitled

<!DOCTYPE html>
<html>

<head>
<style>

    div.myfixedmenu {
           margin-top: -15mm;
           height: 12mm;
           width: 100%; position: fixed; background: blue }

   #theContent {margin-top: 20mm}

</style>

</head>

<body>
<div class="myfixedmenu">
   theCodeForTheMenu
</div>

<div id="theContent">

 <h1>Greetings</h1>
....
</div>
</body>
</html>