I am getting a run -time error 1004 stating it is unable to set the XValues
Property of the Series Class. I don't know why!!!

I did some changes to the old code which was running fine but this code is
annoying me .

Can anybody help plz

Sub SelectCapacity()
Sheets("Numerical Integration").ChartObjects("ChartNumInteg").Activa te
ActiveChart.PlotArea.Select
ActiveChart.ChartType = xlXYScatterSmoothNoMarkers


Select Case CapacityCombo.Value
Case "Exponential"
With ActiveChart
.SeriesCollection(1).XValues = "=AnalysisPageNI!R4C1:R100C1"
.SeriesCollection(1).Values = "=AnalysisPageNI!R4C2:R100C2"
.SeriesCollection(1).Name = "Capacity"
End With

Case "Gumbel"
With ActiveChart
.SeriesCollection(1).XValues = "=AnalysisPageNI!R4C1:R100C1"
.SeriesCollection(1).Values = "=AnalysisPageNI!R4C3:R100C3"
.SeriesCollection(1).Name = "Capacity"
End With
End select

End Sub