C Program for Passing address of a structure variable

/* Passing address of a structure variable */
struct book
{
char  name[25] ;
char  author[25] ;
int  callno ;
} ;
main( )
{
struct book  b1 = { "Let us C", "YPK", 101 } ;
display ( &b1 ) ;
}
display ( struct book  *b )
{
printf ( "\n%s %s %d", b->name, b->author, b->callno ) ;
}