Added ajax to a Link but its not working I added a class use-ajax to a link but Its not updating the wrapper `div. My Code is:

function custom_menu(){
  $items['testing'] = array(
    'page callback' =&gt; 'articlenodeform',
    'access arguments' =&gt; array('access content'),
  );
  $items['customajaxcallback'] = array(
   'page callback' =&gt; 'custom_ajaxcallback',
   'access arguments' =&gt; array('access content'),
  );
  return $items;
}

function articlenodeform(){
   drupal_add_library('system', 'drupal.ajax'); 
   drupal_add_js('misc/ajax.js');
   $link = l(t('Say Hello'), 'customajaxcallback/ajax', array('attributes' =&gt; array('class' =&gt; 'use-ajax')));
   return '&lt;div&gt;'.$link.'&lt;/div&gt;&lt;div id="sayinghello"&gt;&lt;/div&gt;';
}

function custom_ajaxcallback($type = 'ajax') {
  if($type == 'ajax') {
    $output = t('Hello World!');
    $command = array();
    $commands[] = ajax_command_append('#sayinghello', $output);
    $page = array('#type' =&gt; 'ajax', '#ajax_command' =&gt; $commands);
    ajax_deliver($page);
  }
  else{
    return t("Hello world in new page.");
  }
}
I did it : 
The problem was in my callback function : 

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