Custom event placeholder

<?php

add_filter('em_event_output_placeholder','my_em_placeholder_custom_script',100,3);
function my_em_placeholder_custom_script($replace, $EM_Event, $result){
	if ( $result == '#_EVENTBACKBUTTON' ) {
		$replace = $EM_Event->output('<script>alert( " TEST: #_EVENTNAME " );</script>');
	}
	return $replace;
}