As a software programmer, how can I close NJWIN in my program?

On Windows NT/2000/2003/XP/Vista.

SendMessage(FindWindow("NJWIN32",NULL),WM_CLOSE,0);

On Win 95/98/ME.

SendMessage(FindWindow("NJWIN32",NULL),WM_CLOSE,0); 
SendMessage(FindWindow("NJWIN16",NULL),WM_CLOSE,0);