Write test cases for required ZIP code field on a WEB form

[mportnov]

REQIREMENTS (assumptions we make for interview question)
1. The field is required
2. Accepts 5 characters
3. Accepts digits only
4. Input could be either typed in OR pasted
5. More than 5 characters will not be accepted by the field - no error message
6. 1-4 characters - error message with 5 digits reminder
7. Non-existing 5 digits ZIP results in error message ("non-existing...")

TEST CASES:
1. Existing -5 digits 94040 accepted
2. Non-digits/letter 9404O error message (digits only)
3. Non-digit/Sp. Char. 9404@ error message (digits only)
4. Empty field input nothing "required field" message
5. Less than 5 digits 9404 5 digits reminder message
6. Type More than 5 digits 940405 94040 accepted
7. Paste more than 5 digits 940405 94040 accepted
8. Non-existing 5-digit 00001 "non-existing..." message