Question : How can I change the value of a combo box based on value of an unbound text box?

I have a form that creates invoices. What I need to do is have the invoice staus change depending on the value of the total due text box. The combo box (status) has the following set values, Outstanding, Paid, Partial. The (totaldue) text box is an unbound text box the calculates the tax - payments.

Answer : How can I change the value of a combo box based on value of an unbound text box?

How does this textbox calculate the payment? If it's done through code, then you'd do something in the AfterUpdate event of the control (see below, perhaps).

How do you determine the difference between "Outstanding" and Partial"?

Sub YourTextbox_AfterUpdate
  If Me.YourTextbox > 0 Then
    Me.YourCombo = "Outstanding"
  ElseIf Me.YourTextbox = 0 Then
    Me.YourCombo = "Paid"
  End If
End Sub