function showmenu(elmnt)
{
document.getElementById(elmnt).style.visibility="visible"
}
function hidemenu(elmnt)
{
document.getElementById(elmnt).style.visibility="hidden"
}

<!--
function MM_jumpMenu(targ,selObj,restore){ //v3.0
  eval(targ+".location='"+selObj.options[selObj.selectedIndex].value+"'");
  if (restore) selObj.selectedIndex=0;
}
//-->