public void FilterByDateNoneFound()
        {
            clsStockCollection FilterDate = new clsStockCollection();

            FilterDate.FilterByDate(Convert.ToDateTime("01/01/1980"));

            Assert.AreEqual(0, FilterDate.Count);
        }
        public void FilterByDateOk()
        {
            clsStockCollection StockCollection = new clsStockCollection();

            clsStockCollection FilterDate = new clsStockCollection();

            FilterDate.FilterByDate(Convert.ToDateTime("01/01/2090"));

            Assert.AreEqual(StockCollection.Count, FilterDate.Count);
        }
    protected void btnApplyDate_Click(object sender, EventArgs e)
    {
        try
        {
            DateTime ReleaseDate = Convert.ToDateTime(txtReleaseDate.Text);

            clsStockCollection StockCollection = new clsStockCollection();

            StockCollection.FilterByDate(ReleaseDate);

            lstStockCollection.DataSource = StockCollection.StockList;

            lstStockCollection.DataValueField = "productId";

            lstStockCollection.DataTextField = "GameTitle";

            lstStockCollection.DataBind();
        }
        catch
        {
            lblError.Text = "Please enter a date";
        }
    }