;**** DrawEmptyBox *****************************************
; Purpose: Draw an empty box on the screen
; Inputs :
; AL: Color
; DI: Screen location (top-left corner)
; Output : Writes directly to screen
; Description: This routine draws an empty 140x20 box on the
; screen using the palette number specified in AL. Pixels inside
; the box should not be affected by this call.
;**** GetOption
**************************************************************
; PURPOSE: Wait until the option is chosen by user
; Inputs : Options on the the screen
; DI, previous offset (top-left corner of the box)
; MaxOffset, largest offset of box top-left corner
; Output : BX, specifies which option was chosen (1, 2, 3,...)
;**** ShowMenu ****
; Purpose: Showing the user interface menu
; input : AX, number of the menu
; output : Display the disired menu
;========== NOOPTION ===========
; Purpose: show the intructions, then redisplay the Main menu
; input : ax (= 0, main menu), menu required to display
; bx, option number from the menu
; output : bx, option number just select from the main menu
; This should be call when ax = 0