That is, a Web developer can specify that a field is of type numeric and thereafter the field only accepts numbers for input.
Custom responses to invalid data .
In conjunction with data type validation, Web developers have the ability to indicate how the user agent responds to invalid data entry. Client-side field calculations . After setting up an equation using several form fields, a change in one field automatically alters the calculation's results. Application-independent field navigation . An author can stipulate the field order in which navigation occurs, regardless of the user agent accessing the page.