Toolkit Tutorial: Advanced Programming



  
dt_Handle
 
molecule
;


  

/* The null object indicatges an error condition. */

  

molecule
 
=
 
dt_smilin
(
1
,
 
"X"
);

  

if
 
(
NULL_OB
 
==
 
molecule
)

    

printf
(
"The molecule is the null object.\n"
);