Loop statement in assembly error

Question

I've built an assembly program and when I try to loop a label, compile (with 0 errors) and execute, I get this error :

    ntvdm cpu has encountered an illegal instruction

So I remove the code into the label, but i still get that error! And if I remove the loop statement, the program works

Haven't the loop statement the following sintax?

    mov  cx,5
    loop foo
    ;execute foo  5 times

Answer 1

Where's "foo"?

Should be something like:

mov cx,5
foo:
;do stuff
loop foo

Answer 2

An alternative to loop is jmp statement, which has many types eg: je , jg , jnz , jz e.t.c.

mov cx,5;let you want to loop 5 time, move 5 in cx
jmp foo; jumping to foo

;some stuff if you want

foo:

     ;do some thing you want

dec cx;decrease cx by 1
jnz foo; jump to foo if value of cx is not zero

; when value is zero loop will end,any thing further you want to do after loop will comes here