Vigenere cipher encryptor and decryptor

1. You have to type text for cipher and encryption key

2. All useless (not alphabetical) characters will be deleted

3. All the letters are changed for shifts:

a for shift = 1

b for shift = 2

c for shift = 3

and so on.. then:

z for shift = 0

4. For each letter in the text there's shift.

5. Shift the letter.

Examples:

A + 4 = E

Z - 2 = X

5. When list with shifts (keyword list) ends it goes to the start of list.

Example:

meet me at elephant lake

snak es na kesnakes nake

for text "meet me at elephant lake", and keyword "snake"

6. And so on to the end:)