Registration - Fail to check for special characters

[Vo Hung Anh]

when user registers for a new account, user can fill information (Password, retype password, email address, retype email address, capcha confirmation, introducer, time zone and agreement check box) correctly but input special character likes ‘ “ ! ~( ) - + |;,.<>/?@#$%^&*{}[]` into the account name text field. However, system didn't check and display error message for the special characters.