Make Event Form Required Fields

<?php

function required_fields( $validate_post, $EM_Event ){

	if( empty( $_REQUEST['content'] ) ){
		$validate_post = false;
		$EM_Event->add_error( __("Event details is required.","events-manager") );
	}
	if( empty( $_FILES['event_image']['size'] ) ){
		$validate_post = false;
		$EM_Event->add_error( __("Event image is required.","events-manager") );
	}
	if( count($EM_Event->get_categories()) == 0 ){
		$validate_post = false;
		$EM_Event->add_error( __("Event categories is required.","events-manager") );
	}

	return $validate_post;
}
add_filter('em_event_validate','required_fields',100,2);