function checkOnline(requestLink){
    
    new Ajax.Request(requestLink,
              {
                method:'get',
                onSuccess: function(transport){
                  var response = eval("(" + transport.responseText + ")");
                  $$('.onlineStatus').each(function(status){
                      //alert(status.id);
                    statusId = status.id.split('_');
                    if(response.onlineUsers[statusId[1]]){
                        status.src="http://www.atzentreff.de/images/icons/bullet_green_6.png";
                        status.title="online";
                    } else {
                        status.src="http://www.atzentreff.de/images/icons/bullet_red_6.png";
                        status.title="offline";
                    }
                  });
                },
                onFailure: function(){},
                onLoading: function(){}
              });
}