E-mail format is incorrect.
Password must contain 1 number, 1 capital and 1 lowercase letter, and 6-20 digits.
Login successful.
Login failure.
The length of the username only be between three and twenty.
Sign up success.
E-mail has exist.
Username has exist.
Send email success.
Verification code is incorrect.
Confirm password and password are not consistent.
Change password success.
