It seems that what you do it's correct. I also tried it last night, but it fails to load the library whatever I did. Please let me know if you succed in using this from VFP.

Vlad

>>>I will try your pass by reference tomorrow and keep my fingers crossed. The DLL function I am trying to call has a callbank function as one of its arguments. How should I handle this? Does this mean I cannot use this function? If so, I'll have to use VB or VC++.
>>
>>It depends. Can you post here the samples you had in VC++ and VB? If it's an optional parameter (maybe you don't need to pass a callback function, maybe it's just if you want to change a default function?), than you may be able to use it. If it's a mandatory one... no way.
>
>I have included VB and VC++ code below. It looks like the callback function is optional.
>
>Thanks for everyone's help!
>
>********** Visual Basic Code **********
>
>Public Sub Main()
>Attribute Main.VB_Description = "->Used to start this program. Check it out!"
>Dim Err&
>Dim hOrgAPI As Long
>Dim InitFlag As Long
>Dim OrgRegCount As Long
>Dim Error_BadPassword As Boolean
>
>Dim ccMailDir As String
>Dim InfoBuffer As String
>Dim UserName As String
>Dim UserPassword As String
>
>' I cut out a bunch of code here
>
>frmCCMAIL_Start:
> 'If installation is cc:Mail, then show cc:Mail SignIn form
> If GetSetting(Appname:="Organizer BackPack", Section:="Session", Key:="Scheduling") = "cc:Mail" Then
>
> 'Display cc:Mail SignIn form
> ccMailDir = ""
> UserName = ""
> UserPassword = ""
> InitFlag& = OAIF_VALIDATE& Or OAIF_NOUI&
> 'If frmCCMAIL.Tag = "Cancel" then goto Cancel_Pressed
> 'Unload cc:Mail SignIn form
> End If
>
>Session_Start:
> '** {OrgAPIInit} Initialize an Organizer Session **
> hOrgAPI& = OrgAPIInit(0, 0, 0, 0, ccMailDir, UserName, UserPassword, InitFlag&, Err&)
> If hOrgAPI& = 0 Then
>
>' I cut out the rest of program
>
>********** Visual C++ Code **********
>
>// I cut this statement from the top of the C program
>
>/* Function pointer to error display routine */
>LPFNMESSAGEBOX lpfnMsgCallback;
>
>/****************************************************************************
> FUNCTION: ErrorHandler - Callback from InitApi and OrgAPIUIHandleError
> PURPOSE: Print all OrgApi Messages with our own MessageBox
>****************************************************************************/
>//LPFNMESSAGEBOX
>UINT CALLBACK _export ErrorHandler( HWND hWnd, LPCSTR lpszText, LPCSTR lpszCaption, UINT uiFlags )
>{
> LogIt("ErrorHandler %s %s",lpszText, lpszCaption);
> MessageBox( hWnd, lpszText, lpszCaption, uiFlags );
> return 0;
>}
>
>
>/****************************************************************************
> FUNCTION: InitApi
> PURPOSE: Do all the work required to Initialize an API session
>****************************************************************************/
>
>HORGAPI InitApi(HWND hwnd, HINSTANCE hThisInst, HINSTANCE hPrevInst,
> LPSTR lpszContainerPath, LPSTR lpszName, LPSTR lpszNamePassword)
>{
>long OrgAPIInitError;
>HORGAPI hOrgApi=0;
>
>lpfnMsgCallback = ErrorHandler;
>
>if(!APIVersion())
> OrgAPIUIHandleError(hOrgApi, hwnd, lpfnMsgCallback);
>
>hOrgApi = OrgAPIInit(hwnd, hThisInst, hPrevInst, lpfnMsgCallback,
> lpszContainerPath, lpszName, lpszNamePassword,
> OAIF_VALIDATE | OAIF_GRAYDIALOGS, (LPLONG)&OrgAPIInitError );
>
>// I cut out the rest of this function