Get a users id from meta_key and meta_value

get_user_id_by_meta

/**
 * Get User Id from meta_key, meta_value
 **/
function get_user_id_by_meta( $meta_key, $meta_value ) {
	global $wpdb;
	
	$querystr = "SELECT $wpdb->usermeta.user_id FROM $wpdb->usermeta WHERE $wpdb->usermeta.meta_key = '$meta_key' AND $wpdb->usermeta.meta_value = '$meta_value'";

	$results = $wpdb->get_results( $querystr, ARRAY_N );
	
	if ( is_numeric( $results[0][0] ) AND $results[0][0] > 0 )
		return $results[0][0];
	else
		return false;
	
} // end function get_user_id_by_meta