What VFP version are you using? If it's not VFP9 than you have to issue GetLastError() right after call to WIN API, otherwise it can be reset. See http://blogs.msdn.com/calvin_hsia/archive/2005/09/26/474084.aspx

>Sorry. Here is the complete code.
>But both values are empty (0 and "").
>
>==> THIS.nResult_Code = 0 &&(GetLastError(), see below)
>
>Function getextendederror
>LOCAL lcMessage, lnError, lcBuffer
>
>THIS.nResult_Code = GetLastError()
>
>lnError = 0
>lcBuffer = SPACE(MAX_PATH)
>
>InternetGetLastResponseInfo(lnError, @lcBuffer, MAX_PATH)
>
>THIS.nExtended_Result = lnError
>THIS.cExtended_Message = LEFT(lcBuffer, AT(cNULL, lcBuffer) - 1)
>wait window "Aufruf: " + transform(THIS.nExtended_Result) + " " + THIS.cExtended_Message
>
>RETURN
>
>
>
>>The 0 return value indicates the error during FtpCommand execution. What is returned by GetLastError()? You can use Apierror() function from Re: CopyFile API Problems with HP LaserJet 4000 Message #883304 to get a message for GetLastError() code.
>>