sThis snipet of code fails in the with black while trying to set .width = 200

sub a()
Set co = ActiveSheet.ChartObjects.Add(cw * 3, rh * 0.5, cw * 8, rh * 20)
' Name it
co.Name = "ChartExample"

With co.Chart.ChartArea
.Width = 200
End With

end sub