validation

Using validation is really popular nowadays. Most often it is connected to the contact forms.

The principles of validation are rather simple, for example, you can add a text input field as ‘required’ to your form. This means that the web browser will consider this field as mandatory. Different browsers may mark the input box in some way (Firefox 4 Beta adds a red box-shadow by default), display a warning (Opera) or even prevent the form from being submitted if this field has no value. Hopefully these behaviours will converge in future releases: