Option Strict On
Option Explicit On
Public Class Form1
    Dim strfullname() As String
    Private Sub btnDefault_Click(sender As System.Object, e As System.EventArgs) Handles btnDefault.Click
        txtName.Text = "Bryan Chau"
        txtMonth.Text = "6"
        txtID.Text = "123456789"
        txtStart.Text = CStr(Today)
        optTpart.Checked = True
        optPfull.Checked = True
        chkMeal.Checked = False
        chkCare.Checked = False
        txtToddler.Text = "1"
        txtPreschooler.Text = "1"
    End Sub
    Private Function GenID() As String
        strfullname = txtName.Text.Split(" "c)
        Return (strfullname(0).Substring(0, 1) + strfullname(1).Substring(0, 1) + txtID.Text.Substring(0, 4)).ToUpper
    End Function
    Private Function GenName() As String
        strfullname = txtName.Text.Split(" "c)
        Return (strfullname(1) + ", " + strfullname(0))
    End Function
    Private Sub btnCompute_Click(sender As System.Object, e As System.EventArgs) Handles btnCompute.Click
        Dim strFormat1 As String = "{0,-35}{1,13}"
        Dim strFormat2 As String = "{0,-35}{1,13:c2}"
        Dim dtStart, dtEnd As Date
        Dim bytMonth As Byte = CByte(txtMonth.Text)
        Dim bytToddler, bytPreschooler As Byte
        Dim dblMeal, dblCare As Double
        Dim strMeal, strCare As String
        Dim dblToddlerAmt, dblPreschoolerAmt, dblTotalAmt As Double
        dtStart = CDate(txtStart.Text)
        dtEnd = DateAdd(DateInterval.Month, bytMonth, dtStart)
        bytToddler = CByte(txtToddler.Text)
        bytPreschooler = CByte(txtPreschooler.Text)
        If chkMeal.Checked = True Then
            dblMeal = 150 * bytMonth * bytToddler + 200 * bytMonth * bytPreschooler
            strMeal = "Meal plan Required"
        Else
            dblMeal = 0
            strMeal = "Meal plan not needed"
        End If
        If chkCare.Checked = True Then
            dblCare = 100 * bytMonth * (bytToddler + bytPreschooler)
            strCare = "After school care required"
        Else
            dblCare = 0
            strCare = "After school care not needed"
        End If
        If optTFull.Checked = True Then
            dblToddlerAmt = 300 * bytToddler * bytMonth
        Else
            dblToddlerAmt = 200 * bytToddler * bytMonth
        End If
        If optPfull.Checked = True Then
            dblPreschoolerAmt = 450 * bytPreschooler * bytMonth
        Else
            dblPreschoolerAmt = 400 * bytPreschooler * bytMonth
        End If
        dblTotalAmt = dblPreschoolerAmt + dblToddlerAmt + dblCare + dblMeal
        lstInvoice.Items.Clear()
        lstInvoice.Items.Add(String.Format(strFormat1, "Invoice ID ", GenID))
        lstInvoice.Items.Add(String.Format(strFormat1, "Parent Name", GenName))
        lstInvoice.Items.Add(String.Format(strFormat1, "Start Date ", FormatDateTime(dtStart, DateFormat.ShortDate)))
        lstInvoice.Items.Add(String.Format(strFormat1, "End Date ", FormatDateTime(dtEnd, DateFormat.ShortDate)))
        lstInvoice.Items.Add(String.Format(strFormat1, "Number of Toddlers", txtToddler.Text))
        lstInvoice.Items.Add(String.Format(strFormat1, "Number of Preschoolers", txtPreschooler.Text))
        lstInvoice.Items.Add(String.Format(strFormat2, strMeal, dblMeal))
        lstInvoice.Items.Add(String.Format(strFormat2, strCare, dblCare))
        lstInvoice.Items.Add(String.Format(strFormat2, "Toddler amt", dblToddlerAmt))
        lstInvoice.Items.Add(String.Format(strFormat2, "Preschooler amt", dblPreschoolerAmt))
        lstInvoice.Items.Add(" ")
        lstInvoice.Items.Add(String.Format(strFormat2, "Total amt", dblTotalAmt))
    End Sub
End Class