2015-03-19_10-13-45.txt

function custom_ajaxcallback($type = 'ajax') {
  if($type == 'ajax') {
    $output = t('Hello World!');
    $command = array();
    $commands[] = ajax_command_append('#sayinghello', $output);
    $page = array('#type' => 'ajax', '#commands' => $commands); --> In this line
    ajax_deliver($page);
  }
  else{
    return t("Hello world in new page.");
  }
}