adding another control

I'm currently running a report to pull retention data for a certain time
period in my database. The current code I use is:
Dim strWhere As String
Dim stDocName As String
stDocName = "RetentionReport"
strWhere = "[Date] >= #" & _
Forms!CountsReportMenu![FromDate] & "# And [Date] <=#" & _
Forms!CountsReportMenu![ToDate] & "# "

DoCmd.OpenReport stDocName, acPreview, , strWhere

In addition to the date range I'd like to add a line that says to only pull
records where the RetentionEffort field = Yes. Is there a way to add this in
without me messing up my date coding? Thanks!