upgrade.php

<?php
if ( is_admin() ) {

	$installer_wpsms_ver = get_option( 'wp_sms_db_version' );

	if ( $installer_wpsms_ver < WP_SMS_VERSION ) {

		global $wp_statistics_db_version, $table_prefix;

		$create_sms_subscribes = ( "CREATE TABLE {$table_prefix}sms_subscribes(
				ID int(10) NOT NULL auto_increment,
				date DATETIME,
				name VARCHAR(20),
				mobile VARCHAR(20) NOT NULL,
				status tinyint(1),
				activate_key INT(11),
				group_ID int(5),
				PRIMARY KEY(ID)) CHARSET=utf8
			" );

		$create_sms_subscribes_group = ( "CREATE TABLE {$table_prefix}sms_subscribes_group(
				ID int(10) NOT NULL auto_increment,
				name VARCHAR(250),
				PRIMARY KEY(ID)) CHARSET=utf8
			" );

		$create_sms_send = ( "CREATE TABLE {$table_prefix}sms_send(
				ID int(10) NOT NULL auto_increment,
				date DATETIME,
				sender VARCHAR(20) NOT NULL,
				message TEXT NOT NULL,
				recipient TEXT NOT NULL,
				PRIMARY KEY(ID)) CHARSET=utf8
			" );

		require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
		dbDelta( $create_sms_subscribes );
		dbDelta( $create_sms_subscribes_group );
		dbDelta( $create_sms_send );

		update_option( 'wp_sms_db_version', WP_SMS_VERSION );
	}
}
?>