I have the following script I was tinkering around with! And I cant seem to get figure out how to allow toggle of all menus collapsing at once or just one at a time! Am I making sence?

Code:
<html>
 <head>
  <script language="Javascript">
function dis(Menu)
{
el=document.getElementById("menu"+Menu).style;
d=(el.display=="block")?"none":"block"; 
 switch(Menu)
 {
 case 1:
 el.display=d;
 case 2:
 el.display=d; 
 case 3:
 el.display=d;
 case 4:
 el.display=d;
 
 }

}
</script>
<style>
.menu{display:none;}
</style>
 </head>
 <body>
 <div onclick="dis(1);">menu1</div>  
 <div id="menu1" class="menu">sub ****</div>
 <div onclick="dis(2);">menu2</div>  
 <div id="menu2" class="menu">sub ****</div>
 <div onclick="dis(3);">menu3</div>  
 <div id="menu3" class="menu">sub ****</div>
 <div onclick="dis(4);">menu4</div>  
 <div id="menu4" class="menu">sub ****</div>

 </body>
</html>