Bar chart asisstance - year to date sales
 

I am being asked to create a bar chart on a tab that summarizes 2007 and 2008
monthly sales data along with YTD 2009 data.

The boss wants a chart that will "change" each month as data is entered for
2009 sales and them show it in relation to the same YTD period in 2007 and
2008.

Is this possible without having to adjust the data range each month?

Any help will be appreciated.

Jon