OnNavigateError: Called when navigation to a url fails.

procedure YourForm.WebBrowser_OnNavigateError(

  Sender: TObject;

  const pDisp: IDispatch;

  var URL, Frame, StatusCode: OleVariant;

  var Cancel: WordBool);

Command Arguments:

Sender

The TWebBrowser component for which the event is being generated. Usage: (Sender as TWebBrowser)

pDisp

The IWebBrowser component for which the event is being generated. Usage: (pDisp as IWebBrowser)

URL

The URL for which navigation failed.

Frame

The name of the frame involved, or nil if no frame involved.

StatusCode

An error status indicating why the navigation failed. Not always available.

Cancel

Specifies (on exit) whether to cancel the navigation and display an error page (False) or to continue to an "auto-search" page (True).