Open PDF file in web browser new tab

////////////////////////////HTML

<asp:GridView runat="server" ID="GV_ViewPdf" AutoGenerateColumns="false" CssClass="table table-striped table-bordered table-hover table-responsive grd3">

                                    <Columns>

                                        <asp:TemplateField HeaderText="SNo.">

                                            <ItemTemplate>

                                                <%#Container.DataItemIndex+1 %>

                                            </ItemTemplate>

                                            <ItemStyle Width="5%" />

                                            <HeaderStyle Width="5%" />

                                        </asp:TemplateField>

                                        <asp:TemplateField HeaderText="File Names">

                                            <ItemTemplate>

                                                <asp:LinkButton runat="server" ID="Lbtn_ViewPdf" OnClick="Lbtn_ViewPdf_Click" Text='<%#Eval("FileName") %>'

                                                    CommandArgument='<%#Eval("FileURL") %>'></asp:LinkButton>

                                            </ItemTemplate>

                                            <ItemStyle CssClass="text-left" />

                                        </asp:TemplateField>

                                    </Columns>

                                    <RowStyle CssClass="text-center" />

                                    <HeaderStyle CssClass="tblHeadNoWrap" />

                                </asp:GridView>

////////////////////////////////////// CS

protected void Lbtn_ViewPdf_Click(object sender, EventArgs e)

    {

        LinkButton l = sender as LinkButton;

        Session["AllFileSNamePath"] = l.CommandArgument.ToString();

        string url = "ViewTab";

        string script = string.Format("window.open('{0}');", url);

        ScriptManager.RegisterStartupScript(Page, Page.GetType(), "newPage", script, true);

    }

                  

////////// New cs Page

protected void Page_Load(object sender, EventArgs e)

    {

        if (!IsPostBack)

        {

            TestPdf();

        }

    }

    private void TestPdf()

    {

        lblmsg.Text = "";

        string filenamae = Convert.ToString(Session["AllFileSNamePath"]);

        string path = Server.MapPath("~/Resources/" + filenamae);

        if (System.IO.File.Exists(path))

        {

            WebClient client = new WebClient();

            Byte[] buffer = client.DownloadData(path);

            if (buffer != null)

            {

                Response.ContentType = "application/pdf";

                Response.AddHeader("content-length", buffer.Length.ToString());

                Response.BinaryWrite(buffer);

            }

        }

        else

        {

            lblmsg.Text = "Selected file not found";

        }

    }