hyperlinkfield onclick event in gridview

<asp:linkbutton id="lnb" runat="server" text="Edit" commandname="Edit" commandargumnet="<%Eval(" xmlns:asp="#unknown">

<asp:TemplateField HeaderText="No.">
                                    <ItemTemplate>
                                        <asp:HyperLink ID="lbtnBOLNo" runat="server" Text='<%# Eval("No") %>' OnClick="lbtnBOLNo_Click"></asp:HyperLink>
                                    </ItemTemplate>
                                </asp:TemplateField>

protected void lbtnBOLNo_Click(object sender, EventArgs e)
    {
        templbtn = (LinkButton)sender;
        ScriptManager.RegisterStartupScript(Page, this.GetType(), "alert", "window.location='Default2.aspx'; ", true);
    }