Audit Trail

Could not find Field 'Description'

Private Sub Event_Details_DblClick(Cancel As Integer)

On Error GoTo Event_Details_DblClick_Err
    DoCmd.RunCommand acCmdZoomBox
Event_Details_DblClick_Exit:
    Exit Sub

Event_Details_DblClick_Err:
    MsgBox Err.Number & " - " & Err.Description
    Resume Event_Details_DblClick_Exit
End Sub

dAuditTrail   module
******************************
Option Compare Database

Option Explicit

Public Function Audit_Trail(MyForm As Form)

On Error GoTo Err_Audit_Trail
    
'ACC2000: How to Create an Audit Trail of Record Changes in a Form
'http://support.microsoft.com/default.aspx?scid=kb;en-us;197592
    
   ' Dim MyForm As Form
    Dim ctl As Control
    Dim sUser As String
   ' Set MyForm = Screen.ActiveForm
  '  sUser = "User: " & UsersID 'You need to identify your users if you are not using Access security with 

workgroups.
    sUser = Environ("UserName")
    
    'If new record, record it in audit trail and exit function.
    If MyForm.NewRecord = True Then
        MyForm!AuditTrail = MyForm!tbAuditTrail & "New Record added on " & Now & " by " & sUser & ";"
        Exit Function
    End If
    
    'Set date and current user if the form (current record) has been modified.
    MyForm!AuditTrail = MyForm!tbAuditTrail & vbCrLf & vbLf & Now & " " & sUser & ";"
    
    'Check each data entry control for change and record old value of the control.
    For Each ctl In MyForm.Controls
    
    'Only check data entry type controls.
    Select Case ctl.ControlType
    Case acTextBox, acComboBox, acListBox, acOptionGroup, acCheckBox
        If ctl.Name = "tbAuditTrail" Then GoTo TryNextControl 'Skip AuditTrail field.
            'If new and old value do not equal
            If ctl.Value <> ctl.OldValue Then
                MyForm!AuditTrail = MyForm!tbAuditTrail & vbCrLf & ctl.Name & ": From: " & ctl.OldValue & ", 

To: " & ctl.Value
            'If old value is Null and new value is not Null
            ElseIf IsNull(ctl.OldValue) And Len(ctl.Value) > 0 Or ctl.OldValue = "" And Len(ctl.Value) > 0 Then
                MyForm!AuditTrail = MyForm!tbAuditTrail & vbCrLf & ctl.Name & ": From Null, To: " & ctl.Value
            'If new value is Null and old value is not Null
            ElseIf IsNull(ctl.Value) And Len(ctl.OldValue) > 0 Or ctl.Value = "" And Len(ctl.OldValue) > 0 Then
                MyForm!AuditTrail = MyForm!tbAuditTrail & vbCrLf & ctl.Name & ": From: " & ctl.OldValue & ", 

To: Null"
            End If
    End Select
    
TryNextControl:
    Next ctl
    
Exit_Audit_Trail:
    Exit Function
    
Err_Audit_Trail:
    If Err.Number = 64535 Then 'Operation is not supported for this type of object.
        Exit Function
    ElseIf Err.Number = 2475 Then 'You entered an expression that requires a form to be the active window
        Beep
        MsgBox "A form is required to be the active window!", vbCritical, "Invalid Active Window"
    Else
        Beep
        MsgBox Err.Number & " - " & Err.Description
    End If
    Resume Exit_Audit_Trail
    
End Function
*********************************



Before update module in forms
*************************************
Private Sub Form_BeforeUpdate(Cancel As Integer)
On Error GoTo Form_BeforeUpdate_Err
    
   Call Audit_Trail(Me)
   
Form_BeforeUpdate_Exit:
    Exit Sub
    
Form_BeforeUpdate_Err:
    MsgBox Err.Number & " - " & Err.Description
    Resume Form_BeforeUpdate_Exit

End Sub
***************************************************



Doubleclick module in tbAuditTrail controls
***************************************************
Private Sub tbAuditTrail_DblClick(Cancel As Integer)
On Error GoTo tbAuditTrail_DblClick_Err

    Beep
    DoCmd.RunCommand acCmdZoomBox

tbAuditTrail_DblClick_Exit:
    Exit Sub

tbAuditTrail_DblClick_Err:
    MsgBox Err.Number & " - " & Err.Description
    Resume tbAuditTrail_DblClick_Exit

End Sub