How to know the UI element that was clicked?

[Joseph Querijero]

I'm switching from using IE ActiveX to CEFSharp to house a 3rd-party website. It has Submit and Cancel buttons that when clicked, the form should close automatically. I can catch Submit because it navigates to a different URL, but Cancel just switches the text displayed on the page (no navigation happens).  I use AddressChanged for handling Submit in my WinForm, but I can't find a suitable event to use for the Cancel button.