hi, my initials program is failing the cs50 check even when the output is the correct one, I know my code is not probably the best solution, but it works. Thanks in advance for any help.

int main (void) {

string userName;

printf("Write your full name:\n");

userName = get_string();
char space = ' ';


if (userName != NULL) {

    printf("%c", toupper(userName[0]));

    for (int i =1, length = strlen(userName); i < length ; i  ) {


        if ( userName[i] == space) {

            printf ("%c",toupper(userName[i 1]));

        }
    }
    printf("\n");
}

}

this is the result of the cs50 check:

:) initials.c exists :) initials.c compiles :( outputs "MB" for "Milo Banana" \ expected prompt for input, not output of "Write your full name:\n" :( outputs "MB" for "milo banana" \ expected prompt for input, not output of "Write your full name:\n" :( outputs "RTB" for "Robert Thomas Bowden" \ expected prompt for input, not output of "Write your full name:\n" :( outputs "R" for "ROB" \ expected prompt for input, not output of "Write your full name:\n" :( outputs "RTB" for "Robert thomas Bowden" \ expected prompt for input, not output of "Write your full name:\n"