auto changes in chart

[AskExcel]

hi,
i have data source as below and it increases 1 row every month and possible
to have additional bank added in subsequent column.
may i know how to automate the displaying of chart whenever add in 1 month
or when new bank is added?

year month bankA bankB bankC
2008 1 200 300 230
2008 2 230 120 320
add in every month until 12
2008 12 120 210 340
2009 1 340 210 840


thanks
rgds