[SOLVED]"Variable not defined" error

[vigge89]

I've set the variable "WhichFav" to the Index of a control, and when i execute this:

Call saveini("favorites", WhichFav)

I get error saying: "Variable not defined" in the function saveini().

Contents of saveini():

Private Function saveini(KeySection As String, KeyKey As String)
 
Dim lngResult As Long
Dim strFileName
strFileName = App.Path & "\options.ini" 
lngResult = WritePrivateProfileString(KeySection, _
KeyKey, KeyValue, strFileName)
If lngResult = 0 Then
'An error has occurred
Call MsgBox("An error has occurred while saving the options", vbExclamation)
End If
KeyValue = Trim(strResult)
End Function

What is wrong?
Could it be that WhichFav is an integer?
I've tried CStr(WhichFav) but that doesn't work either, same error