Finding dupilcate file using binary search tree (no errors are there.. but no output)

#include <stdio.h>
#include <conio.h>
#include <dos.h>
#include <dir.h>
#include <string.h>
#include <alloc.h>
#include <stdlib.h>

struct btreenode
{
    struct btreenode *leftchild ;
    char data[13] ; /* file name */
    char *loc ; /* location of filename */
    struct btreenode *rightchild ;
} *bt = NULL ;

void disktree( ) ;
int insert ( struct btreenode  **, char*, char* ) ;

void main( )
{
    char current_dir[32] ;

    clrscr( ) ;

    getcwd ( current_dir, 32 ) ;
    chdir ( "\\" ) ;
    disktree( ) ;
    chdir ( current_dir ) ;

    getch( ) ;
}

void disktree( )
{
    struct ffblk file ;
    int flag ;
    char loc[80] ;

    getcwd ( loc, 80 ) ;
    flag =  findfirst ( "*.*", &file, FA_NORMAL | FA_RDONLY | FA_HIDDEN |
		    FA_SYSTEM | FA_LABEL | FA_DIREC | FA_ARCH ) ;

    while ( flag == 0 )
    {
	if ( file.ff_name[0] != '.' )
	{
	    if ( file.ff_attrib == FA_DIREC && file.ff_fsize == 0 )
	    {
		chdir ( file.ff_name ) ;
		disktree( ) ;
		chdir ( loc ) ;
	    }
	    else
		insert ( &bt, loc, file.ff_name ) ;
	}
	flag = findnext ( &file ) ;
    }
}

/* inserts a new node in a binary search tree */
int insert ( struct btreenode  **sr, char* l, char* f )
{
    char *p ;
    int flag ;

    if ( *sr == NULL )
    {
	*sr = ( struct btreenode * ) malloc ( sizeof ( struct btreenode ) ) ;

	if ( *sr == NULL )
	{
	    printf ( "\nOut of memory." ) ;
	    exit(1);
	}

	( *sr ) -> leftchild = NULL ;
	( *sr ) -> rightchild = NULL ;
	strcpy ( ( *sr ) -> data, f ) ;
	p = ( char * ) malloc ( ( strlen ( l ) + 1 ) ) ;

	if ( p == NULL )
	{
	    printf ( "\nOut of memory." ) ;
	    exit(1);
	}

	strcpy ( p, l ) ;
	( *sr ) -> loc = p ;
    }
    else
    {
	flag = strcmp ( ( *sr ) -> data, f ) ;

	if ( flag == 0 )
	{
	    printf ( "org: %s", ( *sr ) -> loc ) ;

	    if ( strlen ( ( *sr ) -> loc ) > 4 )
	    {
		printf ( "\\" ) ;
		printf ( "%s\n", ( *sr ) -> data ) ;
		printf ("dup: %s", l ) ;
	    }
	    if ( strlen ( l ) > 4 )
	    {
		printf ( "\\" ) ;
		printf ( "%s\n\n", f ) ;
	    }
	}
	else if (flag < 0 )
        {
	    insert ( &( ( *sr ) -> leftchild ), l, f ) ;
        }
	else
	    insert ( &( ( *sr ) -> rightchild ), l, f ) ;
    }
    return 0;
}