max date in qlikview

[capriconuser]

I have dates 

Dec 2020, Jan 2021, Feb 2021 till Nov 2021

when i select Dec2020.. then in text object date should be displayed as '-' instead of Nov 2020...

when I select date Dec 2020 text object display Nov 2020.. 

i try this 

=MonthName(vMaxMonth-1)

and vmaxmonth is

=(MonthName(max((Date_Email))))

how I show '-' instead of Nov 2020 ?

[Anil_Babu_Samineni]

Perhaps this?

If(GetSelectedCount(Date_Email)>0, MonthName(vMaxMonth-1), '-')