// Browser Back button and location support functions for AJAX
// Usage: in the main javascript for the page, create a ProcessOnHashChange() function
// and check the hash value.

function al_RenameAnchor(anchorid, anchorname)
{
   document.getElementById(anchorid).name = anchorname;
}

function al_RedirectLocation(anchorid, anchorname, HashName)
{
   //alert("main_redirect");
   al_RenameAnchor(anchorid, anchorname);
   document.location = HashName;
}

function al_GetHashTag()
{
   if (document.location.hash) 
   {
      var HashLocationName = document.location.hash;
      HashLocationName = HashLocationName.replace("#","");
      return HashLocationName;
   }
   else
   {
      return "";
   }
}

function al_CompareHash()
{
   if (al_GetHashTag() != g_al_LastHash)
   {
      g_al_LastHash = document.location.hash;
      ProcessOnHashChange();
   }
}

var g_al_LastHash = "";

// Hook the onhashchange event if present or set an interval for checking it
function al_Init()
{
   if ("onhashchange" in window) 
   {
      window.onhashchange = ProcessOnHashChange;
   }
   else
   {
      // Dummy up the onhashchange event by setting an interval and compare the hash
      // to a the last stored hash
      window.setInterval("CompareHash()", 200);
   }
}