I just wanted to thank all you good people for your help.

I undrestand its close to impossible to correct somebody's mess without even
seeing it, but all your comments and advice got me to the right direction.

I fixed the problem with this code:

' Find the record that matches Text105.
   
   Dim rms As String
 
 
 On Error GoTo HandleErr
   rms = Me.Text105
   
' Set the focus to the last record in the Billing Appointment table.
   Forms![PARTS FORM]![MODEL NUMBER].SetFocus
   DoCmd.GoToControl "[MODEL NUMBER]"
   DoCmd.FindRecord rms, , True, , True

Without you guys I wouldn't even get close to a solution.

Jim

You need a completely different approach to do what you seek.

First, you need to select the combo box value. Second, you need to have the
form's RecordSource query be filtered to that value. Third, you need to move
to the "last" record in the form's data.

Let's tackle number two first. Create a query (call it "qryPartsForm") in
design view. Select the Parts table (or whichever table you're wanting to
use) for the query. Put all the fields in the grid that you want to see/edit
on the form. Under the MODEL NUMBER field, in the Criteria box, put this
expression:
       Forms![PARTS FORM]![Text105]

(Side note:  Are you sure Text105 is a combo box?)

Save and close the query.

Now open the PARTS FORM in design view. Open the Properties window, click on
Data tab, and select qryPartsForm as the Record Source for the form.

Now, put this code as the Event Procedure of the AfterUpdate event of the
Text105 control:

Private Sub Text105_AfterUpdate()
Me.Requery
If Me.RecordsetClone.RecordCount > 0 Then
   Me.Recordset.MoveLast
   Me.[MODEL NUMBER].SetFocus
Else
     MsgBox "No records."
End If
End Sub

Save and close the form.

Now, here is what will happen. When you open the PARTS FORM, the Detail
section will be empty. Select an item from Text105. The form will fill with
the data records and move to the last record and the focus will be put on
the MODEL NUMBER control.