Form to Encrypt/Decrypt using Vigenere-style Cryptography

This particular form handles any string of ASCII characters, encrypts it, and writes the result in a single block of text as a sequence of two-digit numbers (in hex).

Directions:

1. Put in your password (codeword).
2. Put in your plaintext.
3. Click the "encrypt" button. The ciphertext appears. You can then email that to someone, if you want to.
4. Delete the plaintext. Clicking the "decrypt" button restores it from the ciphertext. If someone emailed you some ciphertext, you could decrypt it in the same way.