function getElements(elementName)
{
  return document.getElementsByName(elementName);
}
  
function menu_show(index){

	if(index < 0) return;		
   
   var len = getElements('leftnav2').length;
   var menu = getElements('leftnav2')[index];
   if (menu == null) return;
   if(menu.style.display == 'none' && menu.firstChild.innerHTML != ''){
      menu.style.display = 'block';
	 }else
         menu.style.display = 'none';  
	 for(var i=0;i<len;i++){
	   if(i!=index)
             document.all('leftnav2')[i].style.display='none';
	 }
}