add form::close.

system/form.php

@@ -57,6 +57,16 @@ public static function open_for_files($action = null, $method = 'POST', $attribu
 		return static::open($action, $method, $attributes);
 	}
 
+	/**
+	 * Close a HTML form.
+	 *
+	 * @return string
+	 */
+	public static function close()
+	{
+		return '</form>';
+	}
+
 	/**
 	 * Generate a hidden field containing the current CSRF token.
 	 *