I think I've managed to do that. While aborting request I do:
if (req){ req.abort(); req.is_aborted=true; req=null; } and in error_handler: error_handler:function(xhr, textStatus, errorThrown){ if (textStatus=='timeout' && (!xhr || xhr.is_aborted)){ return true; } alert('Sorry, error occured while loading data. Please, try again...'); }