With many web forms, it's nice to be able to fill out some quick info and hit Enter to submit the form. With .NET where the whole page is a form this can become troublesome when there's multiple submit options on the page. Take this site for instance. When I enter my login info and hit enter I don't want to search the site, so I might want to specify my Login button as the default. In .NET 2.0, along comes the defaultbutton form attribute. Just specify which button you want to be the default (eg. defaultbutton="btnLogin") and you're good to go.