Question

I have a forum and visitors can register user names with more than 20 letters, how can I deny those visitors to register with a (long) user names?

the registration form is using PHP language.

thanks,

Answer 1

You can add a maxlength attribute to your HTML form as a first-step measure.

<input type="text" name="username" maxlength="20" />

On the PHP side, you can use strlen to check the length of your passed parameter.