Bringing aggregated values between two dates

Hi everybody,

I would like to display the sales values from the beginning of the last year until today. However the issue is that I am responded with #error error as a result of the dragging measure KPI onto the crosstab body

LYBegin=ToDate("01.01"+[Year(-1)];"dd.MM.yyyy")

LYToday=ToDate([Day]+"."+[Month]+"."+[Year(-1)];"dd.MM.yyyy")

KPI=Sales Where([CalendarDay]>[LYBegin] And [CalendarDay]<[LYToday])

I need help regarding the issue above.

Regards.

Eddy..