problem to sum negative numbers in array (masm)

Hello all (this is genral masm problem)
i have this code that counts and prints the content of array and it is working great
but when it gets to negative numbers , i dont know how to deal with them . can someone please how
can i sum the array that contains negative numbers ?
here is the code (with positive numbers :
---------------------------------------------------------------------------------------
DSEG SEGMENT
; variables:
RESULT DW ?
INTARRY DW 1,10,128,255,7,150,200,250,21,10
MESS DB 'THE TOTAL IS ','$'

DSEG ENDS
SSEG SEGMENT STACK
DW 100H DUP(?)
SSEG ENDS
CSEG SEGMENT
ASSUME DS:DSEG,SS:SSEG,CS:CSEG
; number of elements:
BEGIN:
MOV [RESULT], 0000H ; CLEAR RESULT
MOV CX, 10 ; COUNT OF ELEMENTS
MOV BX, OFFSET INTARRY ; POINT TO INTARRY
ADD BX,256
MOV SI, 0000H ; FIRST ELEMENT
XOR AX, AX ; CLEAR TOTAL
LP1: ADD AX, [BX + SI] ; ADD VALUE TO TOTAL
INC SI ; NEXT ELEMENT
INC SI
DEC CX
JNE LP1
MOV [RESULT], AX ; STORE TOTAL

MOV DX, OFFSET MESS ; PRINT MESSAGE
ADD DX,256
MOV AH, 9H
INT 21H
MOV AX,[RESULT]
CALL PRINT_AX_2

; wait for any key press:
mov ah, 0
int 16h

PRINT_AX PROC NEAR
PUSH AX
ADD DL,30H
CMP DL,'9'
JBE OK
ADD DL,7
OK: MOV AH,2
INT 21H
POP AX
RET
PRINT_AX ENDP
;***********************************************************
print_ax_1 proc near

MOV CL,4
MOV DL,AL
SHR DL,CL
CALL PRINT_AX
MOV DL,AL

AND DL,0FH
CALL PRINT_AX
MOV DL,AH
SHR DL,CL
CALL PRINT_AX
MOV DL,AH

AND DL,0FH
CALL PRINT_AX
ret
print_ax_1 endp

;***************************************************************
print_ax_2 proc near
MOV CL,4
MOV DL,AH
SHR DL,CL
CALL PRINT_AX
MOV DL,AH
AND DL,0FH
CALL PRINT_AX
MOV DL,AL
SHR DL,CL
CALL PRINT_AX
MOV DL,AL
AND DL,0FH
CALL PRINT_AX
ret
print_ax_2 endp
CSEG ENDS
END BEGIN

--------------------------------------------------------------------------------------------------
but the result is strange when it comes dealing with array that contains negative numbers
say array like that :
INTARRY DW 1,10,128,-255,7,150,200,-250,-21,-10

thanks for the helpers