Checking for Duplicates

[jlegan]

Code below, I have two list boxes. On the left is a list of driver strings and the right is the box that you can use the cmdMove or cmdMoveAll to add items to it. Additionally, there is a manual add text box to add items to the right listbox.

My question is, is there a way to validate and check for duplicates when attempting to add a new one manually or when you refresh the list on the left (which replenishes the list) from adding it again, or letting them add it (disappears from the left) but does not create duplicates on the right?

Thanks,

Jim

Private Sub txtManualAdd_KeyDown(KeyCode As Integer, Shift As Integer)
    If KeyCode = vbKeyReturn Then
        cmdManualAdd.Value = True
    End If
End Sub
 
Private Sub cmdBack_Click()
    ' Move one item from right to left
    If lstRight.ListIndex >= 0 Then
        lstLeft.AddItem lstRight.Text
        lstRight.RemoveItem lstRight.ListIndex
    End If
End Sub
 
Private Sub cmdBackAll_Click()
    ' Move all items from right to left.
    Do While lstRight.ListCount
        lstLeft.AddItem lstRight.List(0)
        lstRight.RemoveItem 0
    Loop
End Sub
 
Private Sub cmdManualAdd_Click()
    ' Verifies that the driver string begins with PCL
    If Not Left$(LCase(txtManualAdd.Text), 5) = "PCL" Then
        MsgBox "The driver string you are attempting to add is not PCL" _
        , vbCritical, "Invalid Driver String"
    Else
        lstRight.AddItem txtManualAdd.Text
    End If
End Sub
 
Private Sub cmdMove_Click()
    ' Move one item from left to right.
    If lstLeft.ListIndex >= 0 Then
        lstRight.AddItem lstLeft.Text
        lstLeft.RemoveItem lstLeft.ListIndex
    End If
End Sub
 
Private Sub cmdMoveAll_Click()
    ' Move all items from left to right
        Do While lstLeft.ListCount
            lstRight.AddItem lstLeft.List(0)
            lstLeft.RemoveItem 0
        Loop
End Sub
 
Private Sub lstLeft_DblClick()
    ' Simulate a click on the Move button.
    cmdMove.Value = True
End Sub
 
Private Sub lstRight_DblClick()
    ' Simulate a click on the Bacl button.
    cmdBack.Value = True
End Sub