This function is provided for legacy code only. Some older plugins may use network messages instead of the panel API. This function wraps the panel API for eased portability into the SourceMod menu system. This function is only usable with the Radio Menu style. You do not need to split up your menu into multiple packets; SourceMod will break the string up internally.
native bool InternalShowMenu(int client, const char[] str, int time, int keys = -1, MenuHandler handler = INVALID_FUNCTION)