reading a line(with spaces) into a string assembly

Question

  ; push stdin here
    push MAX_N             ; maximum number of characters to be read 
    push offset string     ;pointer to an array of chars
    call fgets
    add esp,12

I tried to read into "string" variable a line(with spaces too). I can't do that with scanf so i chose instead to use fgets

But, how can i push standard input there ?