Make a webform submit via Ajax instead of going to a seperate page Doesn't work with Webform 4.x, only with 3.x

template.php

<?php

function hook_form_alter(&$form, &$form_state, $form_id) {
	
	if($form_id == "webform_client_form_22") {
	    // get the nid so we can use it in the wrapper value
		$nid = $form['#node']->nid;
	    // add the ajax properties to the submit button
		$form['actions']['submit']['#ajax'] = array(
			'callback' => 'hook_webform_js_submit', // update function
			'wrapper' => 'webform-client-form-' . $nid,
			'method' => 'replace',
			'effect' => 'fade',
		);
	}
}

function hook_webform_js_submit($form, $form_state) {

    // define the $sid variable (submission id from webform)
	$sid = $form_state['values']['details']['sid'];

    // if we have a sid then we know the form was properly submitted, otherwise, we'll just return the existing $form array
	if ($sid) {
        // first we have to load up the webform node object
		$node = node_load($form_state['values']['details']['nid']);
        // create an array up with the confirmation message, retreived from the webform node
		$confirmation = array(
			'#type' => 'markup',
			'#markup' => check_markup($node->webform['confirmation'], $node->webform['confirmation_format'], '', TRUE),
			);
        // return the confirmation message
		return $confirmation;
	}
	else {
        // return the form
		return $form;
	}
}

?>