Assmebly Timer

[FireFall]

Hi everyone, I am trying to make a timer in assembly.
The user has to type the timer value (in seconds) and a beep occurs when the time is elapsed.

I think i'm not far from the end but i got an error i can't seem to find :/

the program should work like this :
I encode timer value in TIMER

i get actual second from bios and keep it in BH

In a loop i get second from bios and compare it with the value in BH, when the values differ -> i increment a VAR

When var = TIMER i emit a beep

heres where I am

it seems i can't get out of the GETSEC loop, but i dont understand why isnt the JNE working right , i should get out of it every time a second change , right ?

Thanks for all the help u can give me :)
and sorry for the lame french names :( -> french coder here

.MODEL SMALL                                                                                            ;
	.STACK 256                                                                                              ;
	
	.DATA
	RetourLigne     DB "",13,10,"$"
	Chaine1		DB "enter timer value :","$"
	Chaine2		DB "timer is  :","$"
	Chaine3    	DB "test 3",13,10,"$"	
	Chaine4   	DB "test 4",13,10,"$"	
	TIMER 		DB 0
	VAR   		DB 0
	
	.CODE
;*****************************************************;
;             Instruction debut de programme          ;
;*****************************************************;
	mov ax,@data
	mov ds,ax
	
;*****************************************************;
;       Calcul taille fichier                  ;
;*****************************************************;	

	call VALEURTIMER
	call GETSECONDE
	call BEEP
	call FIN

	
;--------------------------------PROCEDURES---------------------------
	
	GETSECONDE proc
	
	TOP:
	MOV AH,2Ch  
	INT 21
	MOV BH,DH   

	GETSEC:      
	MOV AH,2Ch  
	INT 21
	CMP DH,BH    
	
	JNE PRINTA  
	LEA DX,Chaine3
	MOV AH,09H
	INT 21H	
	JMP GETSEC   
	
	
	PRINTA:
	LEA DX,Chaine4
	MOV AH,09H
	INT 21H	
	
	ADD VAR,1d  
	MOV AH,VAR   
	CMP AH,TIMER 
	JE SORTIR   
	JMP TOP     
	SORTIR:
	
	ret
	ENDP


	VALEURTIMER proc
	
	LEA DX,Chaine1
	MOV AH,09H
	INT 21H	
	
	MOV Ah, 01h
	INT 21h
	MOV TIMER, AL
	
	LEA DX,RetourLigne
	MOV AH,09H
	INT 21H	
	
	LEA DX,Chaine2
	MOV AH,09H
	INT 21H	
	
	LEA DX,TIMER
	MOV AH,09H
	INT 21H	
	
	MOV Ah, TIMER
	SUB Ah,30h		; Converti l'ascii en numérique
	MOV TIMER,Ah
	
	ret
	ENDP

	

	BEEP proc
    mov    ah,02h  
    mov    dl,07h   
    int    21h
	
	ret 
	ENDP
	
	;fin du programme
    FIN proc
	mov ax,4C00h
	int 21h
	
	ret 
	ENDP
	
	END