some mistake happened in linking a c++ application?

[jacky]

hi all:
i am porting some application to MIPS.
the all files have compiled. but when i linked the object files there
are some mistake such as:

              undefined reference to `Fl_Browser type_info node'

i know what means of undefined reference is. But i do not know
`Fl_Browser type_info node'.
the Fl_browser is a class. and i can not find any thing about 'type_info
node'.
and i wonder why this kind of mistake happened.
wish someone would give me some advice.
thank you.