New Order

Public Class NewOrderForm
    Dim supplierName As String
    Dim ordernum As Integer
    Dim suppliercode As String
    Private Sub NewOrderForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        getdataset("select supplier_code, supplier_name from suppliers")
        cmbSuppliers.DataSource = ds.Tables(0).DefaultView
        cmbSuppliers.DisplayMember = "supplier_name"
        getdataset("select count(order_code) from Supply_Orders")
        ordernum = ds.Tables(0).Rows(0).Item(0) + 1
        lblOrdera.Text = "Creating order number " & ordernum
    End Sub

    Private Sub btnExitNewOrder_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExitNewOrder.Click
        Me.Hide()


    End Sub

    Private Sub cmbSuppliers_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmbSuppliers.SelectedIndexChanged
        Dim suppliernumber As Integer
        Dim isSupplier As Boolean = False
        Dim i As Integer = 0
        getdataset("Select  Count(Supplier_code) From suppliers")
        suppliernumber = ds.Tables(0).Rows(0).Item(0).ToString
        getdataset("select supplier_code, supplier_name from suppliers")
        While isSupplier = False And i <= suppliernumber - 1
            If ds.Tables(0).Rows(i).Item(1).ToString = cmbSuppliers.Text Then
                isSupplier = True
            Else
                i += 1
            End If
        End While

        If isSupplier = True Then
            supplierName = cmbSuppliers.Text
            getdataset("select supplier_code from suppliers Where supplier_name like '" & supplierName & "'")
            suppliercode = ds.Tables(0).Rows(0).Item(0)
            getdataset("select * from products Where supplier_code like '" & suppliercode & "'")
            cmbProducts.DataSource = ds.Tables(0).DefaultView
            cmbProducts.DisplayMember = "Product_code"
        End If
    End Sub

    Private Sub btnAddItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddItem.Click
        If txtAmount.Text <= 0 Then
            MsgBox("Order must include 1 item or more")
        Else
            Dim isorder As Boolean = False
            getdataset("select count(order_code) from supply_orders")
            Dim currentordernum As Integer = ds.Tables(0).Rows(0).Item(0)
            If currentordernum = ordernum Then
                isorder = True
            End If
            If isorder = False Then
                Dim sqler As String
                sqler = ("Insert into Supply_Orders (Order_code, supplier_code, Worker_Id, Order_date, estimated_arrival_date) values ('" & ordernum & "', '" & suppliercode & "', '" & userID & "', '" & Date.Today & "', '" & Date.Today.AddDays(14) & "')")
                getdataset(sqler)
            End If
            Dim orderedItems As Integer
            Dim isOrdered As Boolean = False
            Dim i As Integer = 0
            getdataset("Select  Count(Order_Code) From Order_Details where order_code like '" & ordernum & "'")
            orderedItems = ds.Tables(0).Rows(0).Item(0).ToString()
            getdataset("Select product_code From Order_Details where order_code like '" & ordernum & "'")
            While isOrdered = False And i <= orderedItems - 1
                If ds.Tables(0).Rows(i).Item(0).ToString = cmbProducts.Text Then
                    isOrdered = True
                Else
                    i += 1
                End If
            End While
            If isOrdered = True Then
                MsgBox("Cannot Order The same Item twice under one order code")
            Else
                btnExitNewOrder.Enabled = False
                Dim strsql As String
                strsql = ("Insert into Order_Details (Order_code, product_code, amount) values ('" & ordernum & "', '" & cmbProducts.Text & "', '" & txtAmount.Text & "')")
                getdataset(strsql)
                lstItemsOrdered.Items.Add(cmbProducts.Text & "    " & txtAmount.Text)
                btnFinishOrder.Enabled = True
                cmbSuppliers.Enabled = False
            End If
        End If
    End Sub

    Private Sub btnFinishOrder_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFinishOrder.Click
        MsgBox("Your order has been submitted!")
        btnExitNewOrder.Enabled = True
        Me.Hide()
    End Sub
End Class