bring back fixed position menu, but fix it from overlapping the theme

simplemenu.css

@@ -14,7 +14,7 @@ background:#ddd;
 border-bottom:1px solid #999;
 font:11px Verdana, Helvetica, sans-serif;
 left:0;
-position:static;
+position:fixed;
 top:0;
 width:100%;
 height:21px;

simplemenu.js

@@ -6,6 +6,7 @@ $(document).ready(function() {
                               
   // insert extra <br /> so menu doesn't overlap theme
   $('<ul id="simplemenu" class="clear-block"></ul>').prependTo('body');
+  $('body').css('margin-top', '23px');
   
   // Drupal menu callback
   $('#simplemenu').load(basePath + 'simplemenu/menu', function() {