var pages = {
  'subnav_one':['pageone.html','pagetwo.html'],
  'subnav_two':['pagethree.html','pagefour.html']
};



for(var i in pages) {
  if(in_array(page(document.location.href), pages[i])) {
    if (document.getElementById(i))
      document.getElementById(i).style.display = '';
    if (document.getElementById(i+'_parent'))
      document.getElementById(i+'_parent').className = 'active';
  } else {
    if (document.getElementById(i))
      document.getElementById(i).style.display = 'none';
  }
} 
function in_array(needle,haystack) {
  for(var i in haystack)
    if(haystack[i] == needle)
      return true;
  return false;
}        
function page(url) {
  apage = url.substring(url.lastIndexOf('/')+1);
  if(apage.indexOf('#') > 0)
    apage = apage.substring(0, apage.indexOf('#'));
  return apage;
}