NetFileEnum

Hi !
i have the following code segment …
i am not getting proper values in the Buffer.
any ideas what i am missing?

char Buffer[1000];
DWORD read,total;
DWORD *dw = NULL ;

NetFileEnum(NULL,NULL,NULL,3,(unsigned char
**)Buffer,MAX_PREFERRED_LENGTH,&read,&total,dw);

regards
-girish