Prompting for letter input in ASSEMBLY, using registers and procedures

Question

I Am trying to expand on this program and allow the user to input the character to put in the matrix, using the register. AL returns a smiley face regardless of input. What do I need to do to make it so I can use larger register inside of L2, the mov al,bufSize uses too small of a register.

I also have a question regard labels that can be a target of a jump instruction inside of another procedure

Using jump instructions how can I write this to use only one loop?

So in my new code i use a jump instruction instead of a loop, but when i watch it in the debugger it reminds me alot of a loop, is it the same thing?

TITLE Color Matrix (ClrMatrix.asm)

Comment !
Displays an  Character in all possible colors
!

INCLUDE Irvine32.inc

BUFFMAX = 128


.data
charPrompt  BYTE "Choose a letter: ",0
buffer  BYTE  BUFFMAX+1 DUP(0)
bufSize BYTE ?


.code
main PROC
    call ChooseCharacter
    call    GenerateMatrix

main ENDP

ChooseCharacter PROC

    pushad
    mov edx,OFFSET charPrompt
    call WriteString
    mov ecx,BUFFMAX
    mov edx,OFFSET buffer
    call ReadString
    mov bufSize,al
    call Crlf
    popad
    ret
ChooseCharacter ENDP


GenerateMatrix PROC
    call Clrscr
    mov  eax,0

    mov  ecx,16
L1: push ecx    ; vary the background colors

    mov  ecx,16
L2: call SetTextColor   ; vary the foreground colors
    push eax
    mov  al,bufSize
    call WriteChar
    pop  eax

    inc  al ; next foreground color
    loop L2

    sub  al,16  ; reset foreground color to zero
    add  al,16  ; select next background color
    call Crlf

    pop  ecx
    loop L1

    mov  eax,7
    call SetTextColor

    exit
GenerateMatrix ENDP

END main

Answer 1

Working code:

TITLE Q16 Color Matrix              (ClrMatrix.asm)

Comment !
Author: Louis Krueger
date:4/17/2014
Displays a defined Character in all possible colors
!

INCLUDE Irvine32.inc


.data
charPrompt  BYTE "Choose a letter: ",0
Character   DWORD ?


.code
;========================================================
main PROC   ;Calls the procedures
;========================================================
    call ChooseCharacter
    call GenerateMatrix

main ENDP
;-----------------------------------------------------------------
ChooseCharacter PROC
;Takes user input character to use as charcter in print
;-----------------------------------------------------------------
    mov edx,OFFSET charPrompt
    call WriteString
    call ReadChar
    mov Character,eax
    call Crlf

    ret

ChooseCharacter ENDP

;-------------------------------------------------------------------
GenerateMatrix PROC
;-------------------------------------------------------------------
    call Clrscr
    mov  eax,0

    mov  ecx,16
L1: push ecx            ; loop for background colors

    mov  ecx,16
L2: call SetTextColor   ; nested loop for foreground colors
    push eax
    mov  eax,Character
    call WriteChar
    pop  eax

    inc  al         ; inc the foreground color
    loop L2

    sub  al,16      ; resets the forground for next iteration
    add  al,16      ; goes to the next background color
    call Crlf

    pop  ecx
    loop L1

    mov  eax,7
    call SetTextColor

    exit
GenerateMatrix ENDP

END main