(IF any one need to show all record in sub form when the combobox is empty or null )
If Len(Me.cboEmployee & vbNullString) > 0 Then
[Forms]![frm_YearCalendar]![subFormTotalDays].Form.Filter = "[EmployeeID] = " & Me.cboEmployee
Else
[Forms]![frm_YearCalendar]![subFormTotalDays].Form.Filter...