A little Help with what I am doing wrong here

Hello, I have got program running and its doing ok, but it keeps giving the wrong answer and I dont know where\what I did wrong. It looks all right to me but I know I am missing something simple I just cant put my finger on it to save my life.
What it should do is find the GCD of two numbers and print that off. Am I not pushing the val1 and val2 right for the GCD function? should I use offset of val1 and val2? Or si there a better way?
Thanks for any help

Code:

TITLE MASM GCD                      (GCD.asm)


; Description:GCD recursive
; 
; Revision date:

INCLUDE Irvine32.inc
.data
myMessage BYTE "GCD Recursive",0dh,0ah,0
myMess2   BYTE "The GCD is = " ,0dh,0ah,0


;first set of nums
val1 DWORD  5
val2 DWORD  20

.code
main PROC
    call Clrscr  

    mov     edx,offset myMessage
    call WriteString        ;write message
    call Crlf                ;new line
    push val1
    push val2
    call GCD
    
    exit
main ENDP

;------------------------------------------------
GCD PROC,
; This finds GCD
; Gets values from stored values
;returns NA

;------------------------------------------------

        xor edx,edx
        mov eax,dword ptr[esp+8] ;dividend
        mov ebx,dword ptr[esp+4] ;divisor
        div ebx              ;eax/ebx
        cmp  edx,0           ;remainder in edx
        je   L1                 ;yes: quit
        call GCD             ;no: call GCD agian
    L1:
        mov eax,ebx             ;move the divisor into eax for printing i.e GCD    
        mov     edx,offset myMess2
        call WriteString
        call WriteInt        ;Display GCD WriteInt uses EAX = qutent
        call crlf
        ret 8                ;clean up the stack
GCD ENDP

END main