shortcode for events archives by a given year/month url

/*
This shortcode will create an events list group by month with a given $_REQUEST month and year

eg.
URL: http://domain.com/archive_page/?year=2013&month=09

Result:

shortcode: [events_list_monthly]

Sep 2013
Event A - 2013/09/15
Event B - 2013/09/16
*/

function em_events_list_by_month(){
	$year = wp_kses_data($_REQUEST['year']);
	$month = wp_kses_data($_REQUEST['month']);

	echo do_shortcode('[events_list_grouped mode="monthly" year="'.$year.'" month="'.$month.'" pagination=0 ]');
}
add_shortcode('events_list_monthly', 'em_events_list_by_month');