[WikimediaMobile] How to use MobileFrontendHooks::onUserLoginForm to add a little message

I would like to have my

function JidanniLoginFormMessage(&$template){global $wgSitename;$template->set( 'header', "（需帳號來編輯者，請聯絡<a href="/index.php?title=User:WikiSysop"><strong>${wgSitename}</strong>管理員</a>。）" ); return true;} $wgHooks['UserLoginForm'][]='JidanniLoginFormMessage';

also work on mobile.

One notices there is $wgHooks['UserLoginForm'][] = 'MobileFrontendHooks::onUserLoginForm';

but I am afraid I need someone to tell me how to proceed.