Form « HTML Controls « ASP.NET Tutorial

4.5.1.form default focus
4.5.2.Use HTML form to layout controls (
4.5.3.Submitting Form Data
4.5.4.Specifying a Default Button
4.5.5.A survey form (C#)
4.5.6.Using validation controls to fill a form. server-side form tag and multiple client HTML form elements
4.5.8.Multiple server forms can be employed as long as only one is rendered at a time