Thread: help with strings..kind of

I'm just learning how to do C programming, and so far its been quite easy since i programmed for some games before, but tonight im a little tired, and stumped. Ive been trying to do this lab for my class. It is supposed to prompt the user for a string, and be able to encode, or decode the string. It seems to be encoding fine, but decoding wont work. I can't seem to figure it out, can you please help? Heres the code i have so far...so close i think! Thanks for your time.

Code:

// Dependencies ------------------------------------------------------------- 
#include <stdio.h>  // For input/output functions. 
#include <string.h>  // For string functions. 
// End dependencies --------------------------------------------------------- 


// Functions ---------------------------------------------------------------- 
/* --------------------------------------------------------------------------+ 
  main - Displays a menu for selection of printing the message, encoding a
    message, or decoding a message

  Returns 
    program status 

  Functional Notes 
    getchar() prevents auto closing of window by expecting an Enter keypress. 
  --------------------------------------------------------------------------*/ 
char in_msg[250] = "";
char out_msg[250] = "";
char encode[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
char decode[] = "HCFGBMNTVZYPKASQUDXIRWEJLOhcfgbmntvzypkasqudxirwejlo";
char t[250]; 
int n;
int j;
int i;
int menu_item = 0;
// ---------------------------------------------------------------------- 
// Display course work items menu. 
// ---------------------------------------------------------------------- 
int main() 
{
  do 
  {
     printf("\t***Lab 09 - Encode/Decode***\n"); 
     printf("\t***Please choose one of the following functions...***\n"); 
     printf("\tdecrypt       <1>\n"); 
     printf("\tencrypt       <2>\n"); 
     printf("\tquit:         <3>\n"); 

     scanf("%d%*c", &menu_item); 

     switch (menu_item)
     { 
       case 1 :
       {
         strcpy (t, in_msg);
         n = strlen (in_msg);
           for ( j = 0 ; j < 53 ; j++)
           {
             for (i = 0 ; i < n ;i++)
             {
               if ( t[i] == encode[j] )
               {
                 t[i] = decode [j];
               }
             }
           }  
         strcpy (out_msg, t);  
         printf("***********************************************************************\n");
         printf("Original Message: %s\n", in_msg);
         printf("Decrypted Message: %s\n", out_msg);  
         printf("***********************************************************************\n");
         strcpy (in_msg, out_msg);
         menu_item = 0;
         break;
       } 
  
      case 2 :
      {
        printf("Please input a new message: ");
        gets(in_msg);
        strcpy (t, in_msg);
        n = strlen (in_msg);
          for ( j = 0 ; j < 53 ; j++)
          {
            for(i = 0 ; i < n ;i++)
            {
              if (t[i] == decode[j])
              {
                t[i] = encode [j];
              }
            }
          }  
        strcpy (out_msg, t);
        printf("***********************************************************************\n");
        printf("Original Message: %s\n", in_msg);
        printf("Decrypted Message: %s\n", out_msg);  
        printf("***********************************************************************\n");
        strcpy (in_msg, out_msg);
        menu_item = 0;
        break;
      }
      case 3 :
      {
        return 0;
      }
      default:
      {
        printf("Not a valid menu choice, please try again");
        break;
      }
    }
} while (menu_item == 0 );


// ---------------------------------------------------------------------- 
// Standard DOS window exit for when running outside the IDE. 
// ---------------------------------------------------------------------- 
getchar();  // Wait for Enter keypress. 
return 0; 
} 
// End functions ---------------------------------------------------------

The * is supposed to throw out the enter when the user presses enter after the integer. Its not really the best way to scan things in because if the user isnt cooperative it would recieve an error, but it works :/

And as to the other reply, i'm not trying to be in your way or anything. If you dont have time to help me, dont worry about it. No one is saying you have to. I figured out the problem on my own... well... a way around it, i dont know how it could really be programmed yet... But im sorry that I wasnt clear enough. But you dont have to be so mean about it? I was asking for help, not demanding it. I know how it is when people ask you for help and not even try to write the program themselves first--people do it to me all the time. But that was NOT what I was doing nor my intention to make you write the program. I tried, and no matter how much i messed with it, i couldnt figure it out. So if you dont want to help, then DONT, or say in a nice way at least that you dont understand. Theres no need to be mean about it. Ask me to rephrase it if YOU dont understand me.
The problem was that it would encode the string, but not decode it correctly. I dont know how to explain it any better than that? so instead of really decoding it, i just saved the original input.... kinda cheap to do it that way, id rather it really decode it.