var timeout = 500;
  var closetimer = 0;
  var ddmenuitem = 0;

  function main_menu_open()
  { main_menu_canceltimer();
  main_menu_close();
  ddmenuitem = $(this).find('div').css('visibility', 'visible');}

  function main_menu_close()
  { if(ddmenuitem) ddmenuitem.css('visibility', 'hidden');}

  function main_menu_timer()
  { closetimer = window.setTimeout(main_menu_close, timeout);}

  function main_menu_canceltimer()
  { if(closetimer)
  { window.clearTimeout(closetimer);
  closetimer = null;}}

  $(document).ready(function()
  { $('#navigationMain > li').bind('mouseover', main_menu_open)
  $('#navigationMain > li').bind('mouseout', main_menu_timer)});