How could i fix the error pointer?

int rot13 (char chIn, char *chOut)f char tempCh; if ((chIn 90)) freturn -1; tempCh = ((chn-65) + 13) % 26; tempCh+-65; chOut-LtempCh ; return 0; int main) char ch-A char encCh; int returnVal; printf ("Encrypting %c ",ch); returnVal-rot13 (ch,&encCh) if (returnVal!-0) printf("Error in rot13 "); exit (1) printf("rot 13 encrypted value is %c ",encCh)