function allow_onclick_content() {  global $allowedposttags, $allowedtags;  $newattribute = "onclick";  $allowedposttags["a"][$newattribute] = true;  $allowedtags["a"][$newattribute] = true; //unnecessary?}add_action( 'init', 'allow_onclick_content' );

function allow_button_onclick_mce($settings) {  $settings['extended_valid_elements'] =  "a[rel|rev|charset|hreflang|tabindex|accesskey|type|name|href|target|title|class|onfocus|onblur|onclick]";  return $settings;}add_filter('tiny_mce_before_init', 'allow_button_onclick_mce');