//<![CDATA[
 function hide() {
   document.getElementById('berlin').style.display = 'none';
   document.getElementById('duesseldorf').style.display = 'none';
   document.getElementById('aachen').style.display = 'none';
   document.getElementById('zuerich').style.display = 'none';
 }
 function show(id) {
   hide();
   document.getElementById(id).style.display = 'block';
 }
 document.writeln('<style type="text/css">#aachen, #berlin, #duesseldorf, #zuerich {display:none;} #content {width:700px;} </style>')
//]]>