update button on web page

I am wondering if you can tell me how to link (wire together) an update button to a detailsview control in a C# asp.net 2010 web page?

I have dragged a detailsview control on to this new web page and I have connected the detailsview control to a linq data source control. I have changed several boundfields to template fields and indicated which template fields are editable by setting the readonly property to false. I have also dragged a button control on to the webpage and I have clicked on the button control so the delegate handler is setup.

However I can not seem to connect the update button to the detailsview control. Thus can you tell me what else I need to do?