Total fields for a changeable number of records

[Geekette]

I am designing a report which will count the number of sales a salesperson makes over a period of time. The report currently breaks with headers and footers on salesdate and salesperson, with total fields in the footers.
example:
="Total for Salesperson " & [saleslname] & " (" & Count(*) & " " & IIf(Count(*)=1," sale","sales&quot & &quot"
="Total for " & [salesdate] & " (" & Count(*) & " " & IIf(Count(*)=1," sale","sales&quot & &quot"

I would like to have in the report footer not only the grand total for all sales, but also the grand total for each salesperson.
example:
Grand Total for Salesperson Jones = 60 sales
Grand Total for Salesperson Smith = 82 sales
Grand Total = 142 sales

My problem is that for any given reporting period, the number of salespersons varies. Salespersons are identified by saleslname, salesfname and salesID#
Any suggestions?