my code doesn't work:

void rot13 (char *s) { if (s == NULL) return; int i; for (i = 0; s[i]; i++) { if (s[i] >= 'a' && s[i] = 'A' && s[i] = 'n' && s[i] = 'N' && s[i]  
 
  ROT13 (rotate by 13 places) is a simple letter substitution cipher that is an instance of a Caesar cipher developed in ancient Rome and used by Julius Caesar who used it in his private correspondence. ROT13 replaces a letter with the letter 13 letters after it in the alphabet. The following table demonstrates the translation in ROT 13 Thus, the translation of the word JULIUS using ROT13 would be WHYVHF. Write a C++ program that asks the user for the name of an input file and translates the contents of that input file using ROT13. Your main function should be responsible for reading the input file and coordinating calls to a value returning function named Rot13 that will do the translation for each character and Write TranslatedChar that will write the translated character to a secondary file. The Rot13 function takes as input the character to be translated and returns the translated character. The second function named Write TranslatedCharwll have two parameters, the translated character and a reference to an ifstream data type for a secondary file named "output.rot13", and write that translated character to this file