how do i redo a combo box lookup if a parameter is entered wrong?

[milton r]

I have built a database where you click on the combo box lookup button and you are prompted to enter a series of queries in order to filter out the desired search result. My problem is that when I enter a wrong value in any of my parameters I get a blank result, and then I can no longer redo the search.So, how do I redo my parameter search by clicking on the lookup button again? I would really appreciate some help here. Thanks

[MOCaseA]

Please post the code you are using.

[MOCaseA]

Here is an example of a filtering system I used:

Private Sub CAR_AfterUpdate()
    SetFilter
End Sub
Private Sub Date_AfterUpdate()
    SetFilter
End Sub
Private Sub System_AfterUpdate()
    SetFilter
End Sub
Private Sub System_POC_AfterUpdate()
    SetFilter
End Sub
Private Sub SetFilter()
    Dim FilterCriteria As String
    If CAR & "" <> "" Then FilterCriteria = FilterCriteria & " AND [CAR]='" & CAR & "'"
    If Date & "" <> "" Then FilterCriteria = FilterCriteria & " AND [Date]='" & Date & "'"
    If System & "" <> "" Then FilterCriteria = FilterCriteria & " AND [System]='" & System & "'"
    If System_POC & "" <> "" Then FilterCriteria = FilterCriteria & " AND [System POC]='" & System_POC & "'"
    If FilterCriteria = "" Then
            Me.FilterOn = False
    Else
        FilterCriteria = Mid(FilterCriteria, 6) 'REMOVE THE LEADING " AND "
        Me.Filter = FilterCriteria
        Me.FilterOn = True
    End If
End Sub

I then made each Filter box into a combo box with the row source being the particular field that I was filtering and no control source. To keep the clutter down I also changed "SELECT" to "SELECT DISTINCT" and then selected yes in the "limit to list" option (to prevent anyone from mistyping anything. It tells the user no matching record found and stops the query until corrected). Not perfect, but functional.