How to add multiple Yaxis

Jun 17 at 4:45 PM
This is my code, only create 1 axis.
    Dim varYAxisItem As Highchart.Core.YAxisItem
    Dim varXAxisItem As Highchart.Core.XAxisItem

    hcVendas.Title = New Title("Tasa de Conversion : " & producto & "")
    hcVendas.SubTitle = New SubTitle("Agrupado por periodos")
    hcVendas.Series.Clear()

    varXAxisItem = New Highchart.Core.XAxisItem() With {.categories = (periodos.ToArray)}
    varYAxisItem = New Highchart.Core.YAxisItem() With {.title = New Title("Totales por Mes")}

    Me.hcVendas.XAxis.Add(varXAxisItem)
    Me.hcVendas.YAxis.Add(varYAxisItem)

    Dim series As New Collection()

    series.Add(New Serie With {.name = "COTIZACIONES", .data = cotiza.ToArray})
    series.Add(New Serie With {.name = "VENTAS", .data = ventas.ToArray})

    ' New Series with a diffent RenderType
    series.Add(New Serie With {.name = "TASA CONVERSION", .data = tasa.ToArray, .type = RenderType.line})
    hcVendas.PlotOptions = New Highchart.Core.PlotOptions.PlotOptionsColumn With {.borderColor = "#dedede", .borderRadius = 4, .zIndex = 1}

    hcVendas.DataSource = series