notebook widget like in Firefox

[Khiraly <khiraly123 gmx net>]

Dear List,

  I'm developing an application in which I'd like the windows to be able
to be grouped on tabs, exactly like Firefox does.
  I've looked into the notebook widget, and it would meet my
expectations - but I cannot place an X (close) button on the right side
of the tabs (one X overall, no Xs for the separate tabs, just like
Firefox).
  This would be a chat window alike those in the popular Xchat2 program,
but I'd like the pages grouped like in the Firefox browser.

  Could someone recommend me a documentation for this? I've checked the
GTK API specifications concerning to the notebook widget, but I see no
information on this. But I really hope there is a solution for this,
either one not in the documentation or one I had skipped.

  All suggestions are welcome.

Best regards,
Khiraly