function roll_over(img_name, img_src)
{
   document[img_name].src = img_src;
}

function getXMLHttp()
{
  var xmlHttp

  try
  {
    //Firefox, Opera 8.0+, Safari
    xmlHttp = new XMLHttpRequest();
  }
  catch(e)
  {
    //Internet Explorer
    try
    {
      xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch(e)
    {
      try
      {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch(e)
      {
        alert("Your browser does not support AJAX!")
        return false;
      }
    }
  }
  return xmlHttp;
}

function requestOverall()
{
  var xmlHttp = getXMLHttp();
  
  xmlHttp.onreadystatechange = function()
  {
    if(xmlHttp.readyState == 4)
    {
      HandleResponse(xmlHttp.responseText);
    }
  }
  xmlHttp.open("GET", "getLeaderboard.php", true); 
  xmlHttp.send(null);
  document["butt_over"].src = "images/new_index/lead_over_on.gif";
  document["butt_kudos"].src = "images/new_index/lead_kudos.gif";
  document["butt_wealth"].src = "images/new_index/lead_wealth.gif";
  document["butt_dev"].src = "images/new_index/lead_dev.gif";
}
function requestKudos()
{
  var xmlHttp = getXMLHttp();
  
  xmlHttp.onreadystatechange = function()
  {
    if(xmlHttp.readyState == 4)
    {
      HandleResponse(xmlHttp.responseText);
    }
  }
  xmlHttp.open("GET", "getLeaderboard_kudos.php", true); 
  xmlHttp.send(null);
  document["butt_over"].src = "images/new_index/lead_over.gif";
  document["butt_kudos"].src = "images/new_index/lead_kudos_on.gif";
  document["butt_wealth"].src = "images/new_index/lead_wealth.gif";
  document["butt_dev"].src = "images/new_index/lead_dev.gif";
}
function requestWealth()
{
  var xmlHttp = getXMLHttp();
  
  xmlHttp.onreadystatechange = function()
  {
    if(xmlHttp.readyState == 4)
    {
      HandleResponse(xmlHttp.responseText);
    }
  }
  xmlHttp.open("GET", "getLeaderboard_wealth.php", true); 
  xmlHttp.send(null);
  document["butt_over"].src = "images/new_index/lead_over.gif";
  document["butt_kudos"].src = "images/new_index/lead_kudos.gif";
  document["butt_wealth"].src = "images/new_index/lead_wealth_on.gif";
  document["butt_dev"].src = "images/new_index/lead_dev.gif";
}
function requestDev()
{
  var xmlHttp = getXMLHttp();
  
  xmlHttp.onreadystatechange = function()
  {
    if(xmlHttp.readyState == 4)
    {
      HandleResponse(xmlHttp.responseText);
    }
  }
  xmlHttp.open("GET", "getLeaderboard_dev.php", true); 
  xmlHttp.send(null);
  document["butt_over"].src = "images/new_index/lead_over.gif";
  document["butt_kudos"].src = "images/new_index/lead_kudos.gif";
  document["butt_wealth"].src = "images/new_index/lead_wealth.gif";
  document["butt_dev"].src = "images/new_index/lead_dev_on.gif";
}
function HandleResponse(response)
{
  document.getElementById('leaderboardDiv').innerHTML = response;
}