How to Create a Default 'Enter' Button
ASP.NET 2.0 introduces the concept of a "default button". The new defaultbutton attribute can be used with a <form> or <asp:panel> control. What button will be "clicked" depends on where the cursor acutally is and what button is choosen as a default button for the form or a panel.
Here is sample HTML code that contains one form and one panel control: