In 2007, how do you link a chart title to a cell?

In my situation, I have a pivot chart and I want the chart title to change
when I change one of the filters. The filters are different sites. I would
like the chart title to change to the one item I select from the list. For
example, I have sites 1, 2 and 3. I select 1 of these, say site 1. How do I
get the chart title to change to "Site 1" automatically?

Thanks,