Mikichi -
1) Make sure the form is bound to the table, and bind the other two fields to the name fields in the table and see if it works without any further effort. It probably will.
If it does not, the reason will be because Access will be complaining that you are trying to change the key field.
If that happens, then try this -
2) Add a new, unbound, combo box to the form, and put this in the afterupdate event of the combo box. In the below code I Called it CboID.
Code:
Private Sub cboID_AfterUpdate()
' Find the record that matches the control.
Dim rs As Object
Set rs = Me.Recordset.Clone
rs.FindFirst "[ID] = " & Str(Nz(Me![cboID], 0))
If Not rs.EOF Then Me.Bookmark = rs.Bookmark
End Sub
Assuming you bound the form to the table, and all three text boxes to fields in the table, that code should cause all three text boxes to update each time the combo box is changed.
If this works, then you should set the ID text box so that the ID data cannot be changed.