This specification defines Web Forms 2.0, an extension to the forms features found in HTML 4.01's forms chapter. Web Forms 2.0 applies to both HTML and XHTML user agents, and provides new strongly-typed input fields, new attributes for defining constraints, a repeating model for Declarative repeating of form sections, new DOM interfaces, new DOM events for validation and dependency tracking, and XML submission and initialization of forms. This specification also standardises and codifies existing practice in areas that have not been previously documented. HTML 4, XHTML 1.1 and the DOM are thus extended in a manner which has a clear migration path from existing HTML forms, leveraging the knowledge authors have built up with their experience with HTML so far.
tips to a better form
handling lots of them - see Web Form Flow