Public Class Form1
    Dim Gname(100) As String
    Dim Shoesize(100) As Integer
    Dim Index, ListCount, NumOfNames As Integer
    Dim Index1, Index2, Index3, TempShoe, tempmax As Integer
    Dim TempName As String
    Dim i As Integer

    Private Sub btnEnterName_Click(sender As Object, e As EventArgs) Handles btnEnterName.Click
        Index3 = Val(TxtEnterShoeSize.Text)
        Dim previous As String
        previous = lblprevious.Text
        If Index3 > previous Then
            lblprevious.Text = Index3
        End If
        Index = Index + 1 'increment Index value
        Gname(Index) = txtEnterName.Text ' allocates Name to Gname array element
        Shoesize(Index) = Val(TxtEnterShoeSize.Text)
        txtEnterName.Text = "" 'clears textbox ready for next data entry
        TxtEnterShoeSize.Text = ("")
        txtEnterName.Focus() 'places cursor in Enter Name textbox
    End Sub

    Function DisplayList()
        lstlistarray.Items.Clear() 'clearing array on program load
        NumOfNames = Index
        For Me.ListCount = 1 To NumOfNames
            lstlistarray.Items.Add(Gname(ListCount) & " " & "has a shoesize of" & " " & Shoesize(ListCount))
        Next
        Return True
    End Function

    Private Sub btndisplaydata_Click(sender As Object, e As EventArgs) Handles btndisplaydata.Click
        Call DisplayList()
    End Sub

    Private Sub btnmax_Click(sender As Object, e As EventArgs) Handles btnmax.Click
        txtmax.Text = lblprevious.Text
    End Sub

    Private Sub btnswaparray_Click(sender As Object, e As EventArgs) Handles btnswaparray.Click
        swap(Gname(txtarrayelement.Text), Gname(txtsecondswap.Text))
        swap(Shoesize(txtarrayelement.Text), Shoesize(txtsecondswap.Text))
        Call DisplayList()
    End Sub

    Function swap(ByRef item1, ByRef item2) 'function same as algorithm for swap
        Dim temp As String = item1
        item1 = item2
        item2 = temp
    End Function

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        lblprevious.Text = 0
        lblprevious.Visible = False
        lstlistarray.Items.Clear()
        Index = 0 ' intialises variables when form loads
        txtEnterName.Focus()
    End Sub

    Private Sub btnDisplayArray_Click(sender As Object, e As EventArgs)
        lstlistarray.Items.Clear() ' clears previous list
        NumOfNames = Index ' used for varying array sizes
        For Me.ListCount = 1 To NumOfNames 'display array elements into list box
            lstlistarray.Items.Add(Gname(ListCount) & " has a shoesize of " & Shoesize(ListCount))
        Next
    End Sub

End Class