I have a worksheet called graphdata and another called charts. on the charts
worksheet there is chart 4. I am trying to dynamically set the range for the
chart as follows

Sheets("Charts").Activate
Range("A1").Select
ActiveSheet.ChartObjects("Chart 4").Activate
ActiveChart.ChartArea.Select
ActiveChart.PlotArea.Select
ActiveChart.SeriesCollection(1).Values = "=GraphData!$B$4:$B" & lastrow
ActiveChart.SeriesCollection(2).Values = "=GraphData!$C$4:$C" & lastrow
ActiveChart.SeriesCollection(3).Values = "=GraphData!$I$4:$i" & lastrow

lastrow is determined by using another and in this particular case is 34.

the actual chart series reads

=GraphData!$B$4:$B$32 and its that last number I want to dynamically change
depending on the number of rows in the data

Any suggestions