Is it possible to determine which SubReport is rendered?

Hi All,

Using SQL 2008  R2 SSRS.

I have a report with a number of subreports, and need to show a different footer image depending on which subreport is on the page.  Each subreport could span multiple pages, so I can use a PageNumber expression to show or hide the image.

So For example:

SR1 (3 pages) - Show Footer A

SR2 (1 page) -  Show Footer A

SR3 (2 pages) - Show Footer A

SR4 (1 Page) - Show Footer B

SR5 (2 pages) - Show Footer B.

I'd even settle for a trigger after SR3 to change the footer image.  Keep in mind that these sub reports may also not contain data and therefore not displayed.

Thanks in advanced.