VigenereCipherDecoder

import javax.swing.*;
/**
 * Vigenere_Cipher decoder
 * Sorry for being to lazy to comment the code, hopefully you can figure it out.
 * @author Kushtrim
 * @version 1.01
 */
public class Vigenere_Cipher

{
    public static void main(String args[])
    {
        String input = JOptionPane.showInputDialog("The ciphertext to be decoded :").toLowerCase();
        String shifra = JOptionPane.showInputDialog("The key :").toLowerCase();
        int[] cipher = new int[shifra.length()];



        for ( int i = 0 ; i !=shifra.length(); i++)
        {
            cipher[i] = shifra.charAt(i) - 96;
           // System.out.println(cipher[i]);
        }

        String answer = "";
        for (int i = 0 ; i<input.length(); i++)
        {

            int index = i%shifra.length();
            char c = decodeLetter(cipher[index] ,input.charAt(i) );

              answer +=c;
        }

        System.out.print(answer);
    }
// this can be done more neatly by using mod ( % in java)
    private static char decodeLetter( int x , char c)
    {

        char r;
        if(c >= 97 && c < (97+26))
        {

            int k = (c -97 -x+1);
            if ( k<0)
            {
                k = 26+k;
            }

            r = (char)( k+97);
        }
        else {
            r= '$';
        }
        return r;
    }
}