function userNameChanged()
{
  var uUrl = '/userData.cgi?user=' + escape($('userName'));
  new Ajax.Request(uUrl, {method: 'GET', onSuccess: userDataReceived});

  var user = null;
  var institution = null;

  function userDataReceived(transport)
  {
    user = parseUserData(transport.responseText);
    if(user.institutionId)
    {
      var iUrl = '/institutionData.cgi?id=' + escape(user.institutionId);
      new Ajax.Request(iUrl, {method: 'GET', onSuccess: institutionDataReceived});
    }
    else
      displayUser(user, null);
  }

  function institutionDataReceived(transport)
  {
    institution = parseInstitutionData(transport.responseText);
    displayUser(user, institution);
  }
}