/** Our one and only request object */
var hRequest = null;
var nTabToBeSelected = -1;

/** Cross browser script for the HTTP request */
function createRequest()
{
  try
  {
    hRequest = new XMLHttpRequest();
    
  } catch (trymicrosoft)
  {
    var hVersions = ["Msxml2.XMLHTTP.7.0", "Msxml2.XMLHTTP.6.0", "Msxml2.XMLHTTP.5.0", "Msxml2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP", "Microsoft.XMLHTTP"];

    for(var i=0; i < hVersions.length; i++) 
    {
      try
      {
        hRequest = new ActiveXObject(hVersions[i]);
        
        if(hRequest) 
          break;
            
      } catch (ex) 
      {
        // Try next one
      }
    }
  }
}

/** For selecting the tab specified by index */
function selectTab(nTab)
{
  if(hRequest == null)
  {
    createRequest(); // Try once..
    
    if(hRequest == null)
    {
      alert("Oops! We ran into trouble loading the contents - pl. enable Javascript and try again.");
      return;
    }
  }
  
  var sURL = "tab" + nTab + ".aspx";
  nTabToBeSelected = nTab;
  
  hRequest.open("GET", sURL, true);
  hRequest.onreadystatechange = renderResponse;
  hRequest.send(null);
}

/** Called by the browser for rendering the response. */
function renderResponse()
{
  if(hRequest.readyState != 4)
    return;
  
  var sNewContents = hRequest.responseText;
  var hContentsNode = document.getElementById("content");
  
  hContentsNode.innerHTML = sNewContents;
  
  for(var i=1; i <= 4; i++)
  {
    if(i != nTabToBeSelected)
      document.getElementById("tab" + i).className="deselected-tab";
    else
      document.getElementById("tab" + i).className="selected-tab";
  }
}

function getQueryVariable(variable) 
{
  var query = window.location.search.substring(1);
  var vars = query.split("&");
  for (var i=0;i<vars.length;i++)
  {
    var pair = vars[i].split("=");
    if (pair[0] == variable) 
    {
      return pair[1];
    }
  } 
  return 2;
}