Partial Class Input
    Inherits System.Web.UI.Page


    Protected Sub DDL_BirthMonth_SelectedIndexChanged(sender As Object, e As EventArgs) Handles DDL_BirthMonth.SelectedIndexChanged
        Dim iMonth As Integer = CInt(DDL_BirthMonth.Text)

        Dim i As Integer
        DDL_BirthDay.Items.Clear()
        Select Case iMonth
            Case 2
                For i = 1 To 29
                    Dim j As New ListItem(i)
                    DDL_BirthDay.Items.Add(j)
                Next
            Case 1, 3, 5, 7, 8, 10, 12
                For i = 1 To 31
                    Dim j As New ListItem(i)
                    DDL_BirthDay.Items.Add(j)
                Next
            Case 4, 6, 9, 11
                For i = 1 To 30
                    Dim j As New ListItem(i)
                    DDL_BirthDay.Items.Add(j)
                Next
        End Select

    End Sub

    Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
        If Not IsPostBack Then
            Dim i As Integer
            Dim j As New ListItem(i)

            Dim iYear As Integer
            iYear = Now().Year


            For i = iYear To iYear - 100 Step -1
                j = New ListItem(i)
                DDL_BirthYear.Items.Add(j)
            Next


            For i = 1 To 31
                j = New ListItem(i)
                DDL_BirthDay.Items.Add(j)
            Next
        End If

    End Sub

    Protected Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
        Dim iBY As Integer = CInt(DDL_BirthYear.Text)
        Dim iBM As Integer = CInt(DDL_BirthMonth.Text)
        Dim iBD As Integer = CInt(DDL_BirthDay.Text)
        Dim M, N As Integer

        Dim i, j, A(4) As Integer
        M = iBY + iBM + iBD

        While M >= 10
            N = M
            For i = 0 To 3
                A(i) = N Mod 10
                N = Math.Floor(N / 10)
            Next
            M = 0
            For i = 0 To 3
                M += A(i)
            Next
        End While


        Session("BY") = DDL_BirthYear.Text
        Session("BM") = DDL_BirthMonth.Text
        Session("BD") = DDL_BirthDay.Text
        Session("V") = M.ToString()
        Response.Redirect("Result.aspx")
        'Response.Write(M.ToString())
    End Sub
End Class