Dim OrderWindow As HtmlWindow
Dim FormElement As HtmlElement

Private Sub NewOrderButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NewOrderButton.Click
    LoadOrderForm()
End Sub

Private Sub LoadOrderForm()
    If (WebBrowser1.Document IsNot Nothing) Then
        With WebBrowser1.Document
            OrderWindow = .Window.OpenNew(New Uri("file://C:\\orderForm.htm"), "")

            ' !TODO: Perform this in the load event handler!
            ' Get order form. 
            Dim ElemCollection As System.Windows.Forms.HtmlElementCollection = .All.GetElementsByName("NewOrderForm")
            If (ElemCollection.Count = 1) Then
                FormElement = ElemCollection(0)
                ' TODO: Resolve this. 
                'FormElement.AttachEventHandler("onsubmit", New HtmlElementEventHandler(AddressOf Form_Submit))
            End If
        End With

    End If
End Sub

Private Sub Form_Submit(ByVal sender As Object, ByVal e As HtmlElementEventArgs)
    Dim DoOrder As Boolean = OrderWindow.Confirm("Once you transmit this order, you cannot cancel it. Submit?")
    If (Not DoOrder) Then
        ' Cancel the submit. 
        e.ReturnValue = False
        OrderWindow.Alert("Submit cancelled.")
    End If
End Sub

        HtmlWindow orderWindow;
        HtmlElement formElement;

        private void LoadOrderForm()
        {
            if (!(webBrowser1.Document == null)) 
            {
                HtmlDocument doc = webBrowser1.Document;
                orderWindow = doc.Window.OpenNew(new Uri("file://C:\\orderForm.htm"), "");

                //!TODO: Perform this in the load event handler!
                // Get order form. 
                HtmlElementCollection elemCollection = doc.All.GetElementsByName("NewOrderForm");
                if (elemCollection.Count == 1) 
                {
                    formElement = elemCollection[0];
                    //!TODO: Awaiting DCR
                    //formElement.AttachEventHandler("onsubmit", new HtmlElementEventHandler(Form_Submit));
                }
            }
        }

        private void Form_Submit(object sender, HtmlElementEventArgs e)
        {
            bool doOrder = orderWindow.Confirm("Once you transmit this order, you cannot cancel it. Submit?");
            if (!doOrder)
            {
                //Cancel the submit. 
                e.ReturnValue = false;
                orderWindow.Alert("Submit cancelled.");
            }
        }