Chen, is what you're doing legal? I believe it is illegal to decompile and observe the binary machine code (disassembly) operations of VFP's executable code (EXE and DLL).
I refer you to VFP9's EULA section 4:
4. SCOPE OF LICENSE. The software is licensed, not sold. This agreement only gives you some rights to use the software. Microsoft reserves all other rights. Unless applicable law gives you more rights despite this limitation, you may use the software only as expressly permitted in this agreement. The software is engineered to allow you to use it in certain ways. You must comply with these technical limitations. For more information about them, see the software documentation.
You may not:
* make more copies of the software than specified in this agreement or allowed by applicable law, despite this limitation,
* publish the software for others to copy,
* rent, lease or lend it, or
* use it for commercial software hosting services.
>The bug has been fixed in VFP Advanced, please refer to:
>
http://baiyujia.com/vfpdocuments/f_vfp9fix20.asp