问如果用户在textbox2 (即预订日期)后一周内取消门票，将收取总门票费用的5%。

EN

    Function CalcAmt(pDate1 As Date, pDate2 As Date,TicketPrice as Currency) As Currency
    NumDays = DateDiff("d", pDate1, pDate2)

        if NumDays >=7 then
            CalcAmt = 0
        elseif NumDays > 3 then
            CalcAmt = 0.05 * TicketPrice
        else
            CalcAmt = 0.10 * TicketPrice  
        end if
       End Function

Dim currentDate As Date = DateTime.Parse(textbox1.Text)
Dim bookingDate As Date = DateTime.Parse(textbox2.Text)
Dim difference As Integer = bookingDate.Subtract(currentDate).Days