Visual Basic

'This is the Standard Module'
Option Strict On

Module Module1

Public Sub AddToOrder(ByVal intTotalSales As Integer, ByRef dblSubtotal As Double)

        dblSubtotal = dblSubtotal + intTotalSales

End Sub

Public Function Taxes() As Double

Dim dbltaxRate As Double = 0.07
Dim dblSubtotal As Double

Return CDbl(dblSubtotal * dbltaxRate)


End Function


End Module

Option Strict On
Public Class frmDisplay

    Private Sub btnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClose.Click

        'Closes the Bill 
        Me.Close()

    End Sub

    Private Sub frmDisplay_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'When the form is loaded, the date is going to appear as well as the total amount due for all coffee ordered'

        Dim todayDate As Date = Today
        txtBoxDate.Text = todayDate.ToString

        'declare'
        Dim decSalesTax As Decimal
        Dim decSubtotal As Decimal
        Dim dblSubtotal As Double
        Dim intTotalSales As Integer
        
        'calculate'
        decSalesTax = CDec(Taxes())
        decSubtotal = AddToOrder(intTotalSales, dblSubtotal)

        'display'
        txtBoxSubtotal.Text = decSubtotal.ToString
        txtBoxTax.Text = decSalesTax.ToString
        txtBoxTotal.Text = txtBoxSubtotal.Text + txtBoxTax.Text


    End Sub


End Class

'data tier

Imports System.Data

Public Class RoomsDataTier

    ' Module-level variables.
    Private ARoomTableAdapter _
      As CottagesDataSetTableAdapters.RoomsTableAdapter
    Private ABedsTableAdapter _
      As CottagesDataSetTableAdapters.BedsTableAdapter
    Private ACottagesDataSet As CottagesDataSet

    Public Sub New()
        Try
            ' Instantiate the TableAdapters and DataSet.
            ABedsTableAdapter = New  _
              CottagesDataSetTableAdapters.BedsTableAdapter()
            ARoomTableAdapter = New  _
              CottagesDataSetTableAdapters.RoomsTableAdapter()
            ACottagesDataSet = New CottagesDataSet
            ' Fill the DataSet.
            ARoomTableAdapter.Fill(ACottagesDataSet.Rooms)
            ABedsTableAdapter.Fill(ACottagesDataSet.Beds)
        Catch ex As Exception
            Throw ex
        End Try
    End Sub

    Public Function GetDataSet() As CottagesDataSet
        ' Return the DataSet.

        Return ACottagesDataSet
    End Function
End Class

Imports System.Data
Public Class Rooms

    ' Module-level variables.
    Private AroomsDataTier As RoomsDataTier
    Private AcottagesDataSet As CottagesDataSet
    Private RoomsBindingSource As BindingSource
    Private BedsBindingSource As BindingSource

    Private Sub StoreForm_Load(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles MyBase.Load
        ' Set up the data for the combo box and text boxes.

        Try
            AroomsDataTier = New RoomsDataTier
            AcottagesDataSet = AroomsDataTier.GetDataSet

            ' Set up stores binding source.
            RoomsBindingSource = New BindingSource
            With RoomsBindingSource
                .DataSource = AcottagesDataSet
                .DataMember = "Rooms"
                .Sort = "Room"
            End With

            ' Bind the form controls.
            With RoomComboBox()
                .DataSource = RoomsBindingSource
                .DisplayMember = "Room"
                .ValueMember = "BedCode"
                .DataBindings.Add("text", RoomsBindingSource, _
                  "Room", False, DataSourceUpdateMode.Never)
                .SelectedIndex = -1
            End With
           
          
            ' Set up the  binding source.
            BedsBindingSource = New BindingSource
            With BedsBindingSource
                .DataSource = AcottagesDataSet
                .DataMember = "Beds"
            End With
        Catch ex As Exception
            MessageBox.Show("Error: " & ex.Message)
        End Try
    End Sub

    

    Private Sub RoomNameComboBox_SelectionChangeCommitted( _
      ByVal sender As Object, ByVal e As System.EventArgs) _
      Handles RoomComboBox.SelectionChangeCommitted
        ' Retrieve the sales information for the grid.
        Dim RoomsString As String
        Static GridInitializedBoolean As Boolean

        ' Retrieve the ID of the selected store.
        RoomsString = RoomComboBox.SelectedValue.ToString
        RoomCheckBox1.DataBindings.Add("CheckState", RoomsBindingSource, "MyColumn", False, DataSourceUpdateMode.OnPropertyChanged, DBNull.Value)
        ' Initialize the grid's binding.
        If Not GridInitializedBoolean Then
            ' Bind and format the grid.
            DataGridView1.DataSource = BedsBindingSource

            GridInitializedBoolean = True
        End If

        ' Filter the grid's data.
        BedsBindingSource.Filter = "BedCode = '" & RoomsString & "'"
    End Sub
end class