I am attempting to use the following code to validate whether or not a user has logged into the database before. It pulls the users windows log in username and checks to see if it is in the tblUsers file. I haven't placed anything in the results of the condition because I haven't acheived a successful if then else statement yet. Can someone let me know if they see an error in this code? Thanks!
Code:
Private Declare Function apiGetUserName Lib "advapi32.dll" Alias _
"GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Function fOSUserName() As String
'Returns the network login name
Dim lngLen As Long, lngX As Long
Dim strUserName As String
strUserName = String$(254, 0)
lngLen = 255
lngX = apiGetUserName(strUserName, lngLen)
If lngX <> 0 Then
fOSUserName = Left$(strUserName, lngLen - 1)
Else
fOSUserName = ""
End If
End Function
Public Function IsNothing(ByVal varValueToTest) As Integer
'-----------------------------------------------------------
' Function Purpose: Tests for results that have no value
' Null = Nothing
' Empty = Nothing
' Number = 0 is Nothing
' String = "" is Nothing
' Date/Time is never nothing
' Inputs: A value to test for logical "nothing"
' Outputs: True = value passed is a logical "nothing", False = value passed has valid data
' Created By: JLV 01/31/95
' Last Revised: JLV 01/31/95
'-----------------------------------------------------------
On Error GoTo IsNothing_Err
IsNothing = True
Select Case VarType(varValueToTest)
Case 0 'Empty
GoTo IsNothing_Exit
Case 1 'Null
GoTo IsNothing_Exit
Case 2, 3, 4, 5, 6 ' Integer, Long, Single, Double, Currency
If varValuetToTest <> 0 Then IsNothing = False
Case 7 ' Date/Time
IsNothing = False
Case 8 ' String
If (Len(varValueToTest) <> 0 And varValueToTest <> " ") Then IsNothing = False
End Select
IsNothing_Exit:
On Error GoTo 0
Exit Function
IsNothing_Err:
IsNothing = True
Resume IsNothing_Exit
End Function
Private Sub Form_Load()
Dim strUser As String
Dim strCondition As String
Dim Result As Integer
Dim Validation As String
strUser = fOSUserName()
strCondition = "[idUser] = " & strUser
If IsNothing(DLookup("[idUser]", "tblUsers", strCondition)) Then
MsgBox "Nothing", vbOKOnly, "Test"
Result = acDataErrContinue
Else
MsgBox "Data Present", vbOKOnly, "Test"
Result = acDataErrAdded
End If
End Sub
