I am compiling my source code which is calling "fitsio.h" file from fits library , and then in fitsio.h another header file is getting called named longname.h , this ffclos , ffgpxv all are defined in "longnam.h" .While I am compiling its giving error message :

usimage.cpp
Generating Code...
Linking...
Creating library .\Output/gci2.lib and object .\Output/gci2.exp
cam_simulator.obj : error LNK2001: unresolved external symbol _ffclos
cam_simulator.obj : error LNK2001: unresolved external symbol _ffgpxv
cam_simulator.obj : error LNK2001: unresolved external symbol _ffthdu
cam_simulator.obj : error LNK2001: unresolved external symbol _ffgisz
cam_simulator.obj : error LNK2001: unresolved external symbol _ffgidm
cam_simulator.obj : error LNK2001: unresolved external symbol _ffghdt
cam_simulator.obj : error LNK2001: unresolved external symbol _ffghdt
.\Release/gci2.dll : fatal error LNK1120: 8 unresolved externals
Error executing link.exe.
PixCel.exe - 8 error(s), 3 warning(s)