Two questions:

1. I create pivot table from data available in a specific range of cells. The data to these cells changes over time. And I want the data change to have an effect on the Pivot table. What happens in if by mistake, I leave the data range empty and click refresh, the pivot table field settings are gone since there is no data available. Is there a way that I can lock or prevent Refresh until the appropriate data is available on the cells?

2. the Pivot tables have a specific data source. however while performing calculations, I delete some columns and rows. And accidentally, if I press Refresh, the data source is changed to whatever rows and columns are available. Is there a way to lock the pivot table data source? - as in the pivot tables have to be generated from the 10 columns only.

Many Thanks,
Booo