// Contains common functions.

// Gets a new instance of the appropriate request object for the user's browser.
function getRequest()
{
  var request;

  try
  {
    // firefox, opera 8.0+, safari
    request = new XMLHttpRequest();
  }
  catch (e)
  {
    // IE 6.0+
    try
    {
      request = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e)
    {
      try
      {
        // IE 5.5+
        request = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch (e)
      {
        // browser doesn't support ajax
        request = null;
      }
    }
  }

  return request;
}