Changing listbox code to work in a userform

I wanted my listbox to be in my userform. However when I try to code it in the way that makes sense to me I keep throwing this error, "The item with the specified name wasn't found." And highlights:

Call UserForm1.ListBoxFunction(ar())

This is the part from the module:

Call calluserform(ar())

Function calluserform(ar() As String)
    Call UserForm1.ListBoxFunction
End Function

This is the part from the userform:

Function ListBoxFunction(ar() As String)
Dim Count As Integer, i As Integer, j As Integer, n As Integer
Dim SummaryWks As Worksheet
Dim LB As ListBox


Set SummaryWks = Worksheets("Summary")
Set LB = SummaryWks.OLEObjects("TowerTypeLB").Object


Count = 0
n = 3

For i = 0 To LB.ListCount - 1
    'check if the row is selected and add to count
    If LB.Selected(i) Then Count = Count + 1
Next i

'based on the above count declare the array
ReDim ar(Count)

j = 0
For i = 0 To LB.ListCount - 1
    If LB.Selected(i) Then
        'if selected then store the item from the
        'first column in the array. change 1 to the
        'respective column number
        ar(j) = LB.List(i)
        j = j + 1
    End If
Next i
End Function

Anyone have any ideas how to go about solving this problem?