Custom Toolbar for Netscape Browser

[Brian Utt]

I am attempting to write an application that sets up a custom toolbar
for
the netscape browser (in much the same way that google and yahoo have
done).
Is there an API that I can work with in order to find out how to start?
Or
does anyone have any idea as to how I can find out more information on
working with the Netscape brower (Navigator and/or Communicator).   I am
sorry to bother this newsgroup, it's just that I haven't found any help
anywhere else.

Thanks!

-Brian Utt