[ns] when add new class in ns2.30, undefined refrence to vtable error

[ghada]

Hi all,

i try to add new simple class to ns2.30
i write the myclass.cc file and .h file, then make ./configure , ./make 
i had this error:

in function myclass::myclass(): undefined refrence to vtable for myclass.

anyone know what it is the error exactly?



thanks