Add/Remove PivotField upon ListBox Selection

I wrote some code for a ListBox that aims at adding/removing corresponding PivotFields that are clicked within a ListBox. For example, when VOL 1 is selected in the ListBox, I want my PivotTable to add the VOL 1 PivotField item. If VOL 1 is deselected in the ListBox, I want my PivotTable to remove the VOL 1 PivotField item. VOL 1 is ListBox count item '0' and I will add additional ListBox items after I can get one to work. Here's my code:

Private Sub ListBox1_Change()

Dim i As Long

With ListBox1
For i = 0 To .ListCount - 1

If .Selected(0) Then
ActiveSheet.PivotTables("PivotTable2").AddDataField ActiveSheet.PivotTables( _
        "PivotTable2").PivotFields("VOL 1"), "Count of VOL 1", xlCount
    With ActiveSheet.PivotTables("PivotTable2").PivotFields("Count of VOL 1")
        .Caption = "Sum of VOL 1"
        .Function = xlSum
        .NumberFormat = "$#,##0.00"
    End With

Else
ActiveSheet.PivotTables("PivotTable2").PivotFields("Sum of VOL 1").Orientation _
        = xlHidden

End If
Next i
End With

End Sub

I get the following errors:
Upon ListBox item selection: PivotTable field name already exists
Upon ListBox item deselection: Unable to get the PivoFields property of the PivotTable class

I'm sure this isn't a very difficult proplem to solve, but I have been unable to figure it out! Any assistance would be greatly appreciated!

No reason for having count and then switching to sum. The macro recorder just recorded the code like that.

I used your code and am still getting some errors, but if the errors weren't there the function would perform fine as it looks like the code is adding and removing the data.

Sub ListBox1_Change()

Dim PT As PivotTable
Set PT = ActiveSheet.PivotTables("PivotTable2")
Dim i As Long

With ListBox1
For i = 0 To .ListCount - 1

If .Selected(0) Then
PT.AddDataField PT.PivotFields("VOL 1"), "Sum of VOL 1", xlSum
    PT.PivotFields("Sum of VOL 1").NumberFormat = "$#,##0.00"
    
Else
PT.PivotFields("Sum of VOL 1").Orientation = xlHidden

End If
Next i
End With

End Sub

I get the following errors:
Upon ListBox item selection: Application-defined or object defined error
Upon ListBox item deselection: Unable to get the PivoFields property of the PivotTable class

Hey romper, I really appreciate your help!! One thing I noticed with the listbox macro: as additional listbox items are selected, the code runs slower and slower (it takes longer and longer for the pivotfields to be displayed). This seems to only be happening with the items that require number format.

Any ideas on what's slowing it down so much?

Hey romperstomper, I ended up using your code and adding the following line: On Error Resume Next. This fixed the issues with the debut window popping up. Everything is working fine now! Thanks again for your help.

Wow, that's perfect! You are the man!