function selectMenu(menuItem)
  {  
    // select the menu item
    var item = document.getElementById(menuItem);
    item.className = "menu_item_sel";
  }
  
  function imposeMaxLength(obj, maxlen)
  {
    // impose a maximum length on text areas   
    var msg = document.getElementById("invalid_msg");

    if (obj.value.length > maxlen)
    {
      obj.value = obj.value.substring(0, maxlen);
      msg.innerHTML="<span class=\"invalid\">Maximum message length exceeded</span>";
    }
    else
      msg.innerHTML = "&nbsp;";    
  }

  // button functions ///////////////////////////////////////////////////////////////////////
  function buttonover(button)
  {
    // called by ordinary HTML buttons on a mouse over event
    if (button.className == '')
      button.className='hover';
    else
    if (button.className == 'alt')
      button.className='alt hover';    
  }

  function buttonout(button)
  {
    // called by ordinary HTML buttons on a mouse out event
    if (button.className == 'hover')
      button.className='';
    else
    if (button.className == 'alt hover')
      button.className='alt';    
  }