[Face]

function change_status() {
   if(document.getElementById("dvprod").style.display == "none"){
      document.getElementById("dvprod").style.display="block";
   }
   else {
      document.getElementById("dvprod").style.display="none";
   }
}

<div id=dvprod align=center style='display:none'>
<table>
...
</table>
</div>