>If I have developed a system, do I need to rewrite some coding in order to place the system on web? Such as change and access to database in ODBC method or need to write java script to update the database in vfp?
No, you can continue to use Visual FoxPro. Check out:
http://www.west-wind.com/articles.htmThere are several articles that describe how this works and the tools that are available to you from Microsoft and third parties like my company.
Regards,