If you use the datepicker class, there are two bugs that you need to adjust for, one minor and one major.
In the datepicker container, the wcpropsave has a type listing a nonexistant property "alue". Delete that property from the list.
The major one is the month display does not display when the dropdpwn is active, so you have no way to ever know what month is the current month.
In the webcalendar container, in the ref4reshmonth method change:
This.Header.CurrentMonth.Value = Month(m.lFirstDate)
with this:
This.Header.CurrentMonth.Value = CMONTH(DATE(m.tnYear, MONTH(m.lFirstDate),1)) + " " + Str(m.tnYear,4,0)
That will fix the display.