Setting a default button in .NET
13 Nov 2007
One way is to use a class like this to add an onkeydown client event to a to a textbox.
Another easier and quicker alternative is to place all the form elements in an ASP.NET Panel and then define the panel’s default button property, like this:
But of course if you are using a LinkButton, then its a whole another ball game. None of the techniques described above might work for you. But you are in luck, this page has what you need to get around that - Using Panel.DefaultButton property with LinkButton control in ASP.NET