I am trying to make a program that will compute and print the factorial of an integer read in from a user. The current code I have is not working, I am getting lots of errors at lines saying there is a syntax error in instruction but I don’t understand what is wrong with it.

.CODE
_MainProc PROC
    ; Print the prompt
    output prompt

    ; Read the number
    input num, 4

    ; Convert input to integer
    atod num
    mov ecx, eax

    ; Check if the number is negative
    cmp ecx, 0
    jl negative_number

    ; Check if the number is 0
    cmp ecx, 0
    je zero_number

    ; Compute factorial
    mov eax, 1            ; EAX will hold the result
    mov ebx, 1            ; EBX will be the counter

factorial_loop:
    cmp ebx, ecx          ; Compare counter with input number
    jg factorial_done     ; If counter > input, we are done
    imul eax, ebx         ; Multiply EAX by counter
    inc ebx               ; Increment counter
    jmp factorial_loop    ; Repeat the loop

factorial_done:
    ; Convert result to string
    dtoa result, eax      ; Convert the integer result to a string

    ; Print the result message
    output result_msg

    ; Print the factorial result
    output result

    ; Exit program
    exit

negative_number:
    ; Print the negative number message
    output neg_msg
    jmp exit_program      ; Exit program

zero_number:
    ; Print the result message
    output result_msg
    ; Print '1' for factorial of 0
    output one
    jmp exit_program      ; Exit program