// extract the file name from a URL 
//("if input is /files/index.html", output is "index")
function extractPageName(hrefString)
{
  var arr = hrefString.split('.');
  arr = arr[arr.length-2].split('/');
  return arr[arr.length-1].toLowerCase();		
}

// search through all the links in array, if one points to
// the same file, apply the class .current to it and to its parent
function setActiveMenu(arr, crtPage)
{
  for(var i=0; i < arr.length; i++)
  if(extractPageName(arr[i].href) == crtPage)
  {
    arr[i].className = "current";
    arr[i].parentNode.className = "current";
  }
}

// call this method from your page
function setPage()
{
  if(document.location.href) 
    hrefString = document.location.href;
  else
    hrefString = document.location;

	if (document.getElementById("menu")!=null)
	  setActiveMenu(document.getElementById("menu").getElementsByTagName("a"), extractPageName(hrefString));
}