INT 50 - PCIBM PC Thuis Organizer Shell - DO MENU
	AX = 0008h
	ES:BX -> menu structure
Return: AL = index 1 or FFh if not selected
	AH = index 2 or FFh if not selected
	BL = index 3 or FFh if not selected
	BH = index 4 or FFh if not selected
SeeAlso: AX=0005h"PCIBM PC Thuis",AX=0007h,AX=000Ch