The code below was supplied by Susan Sale harkins for simple audit tracking.  
I have two issues with it.  Can anyone help me?  
1.  It only works with text box changes.  I would like it to also work with
combo box changes.

2.  I does insert a record for each field changed but it also inserts
anywhere from 8 to 13 additional record on fields that were not changed.  The
additinal inserts slows down record process.  How can i  only insert a record
for only fields that have changed?

Thanks in advance

Code
Sub AuditTrail(frm As Form, recordid As Control)
'track Changes to data
'recordid identifies the pk fields corresponding
'control in form, in order to id record
Dim ctl As Control
Dim varbefore As Variant
Dim Varafter As Variant
Dim strcontrolname As String
Dim strsql As String
On Error GoTo Errhandler
'Get changed values
For Each ctl In frm.Controls
   With ctl
   'avoid labels and other controls with value property
   If .ControlType = acTextBox Then
       If .Value <> OldValue Then
       varbefore = .OldValue
       Varafter = .Value
       strcontrolname = .name
       'Build Insert into statement
       strsql = "insert into " _
           & "audit (Editdate, user, recordid, sourcetable, " _
           & " sourcefield, beforevalue, aftervalue) " _
           & "Values (Now(), " _
           & cDQ & Environ("username") & cDQ & ", " _
           & cDQ & recordid.Value & cDQ & ", " _
           & cDQ & frm.RecordSource & cDQ & ", " _
           & cDQ & .name & cDQ & ", " _
           & cDQ & varbefore & cDQ & ", " _
           & cDQ & Varafter & cDQ & ")"
            '
       'View evaluated statement in Immediate Window.
       Debug.Print strsql
       DoCmd.SetWarnings False
       DoCmd.RunSQL strsql
       DoCmd.SetWarnings True
       End If
   End If
   End With
   Next
   Set ctl = Nothing
   Exit Sub
   
Errhandler:
       MsgBox Err.Description & vbNewLine _
       & Err.Number, vbOKOnly, "Error"
End Sub