load js path in partial page load in asp.net

<script>
        function pageLoad(sender, args) {
            if (args.get_isPartialLoad()) {

                //this is what i have to call but this in external file
                //$(document).ready(function () {
                //    $('[data-toggle="tooltip"]').tooltip();
                //});

               document.appendChild("<script src='js/tooltip.js'>< /script>");
            }
        }
    </script>

<form id="form1" runat="server">
        <div>
            <asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
            <asp:UpdatePanel ID="UpdatePanel1" runat="server">
                <ContentTemplate>
                    <div class="container">
                        <h3>Tooltip Example</h3>
                        <a href="#" data-toggle="tooltip" title="Hooray!">Hover over me</a>
                    </div>
                    <asp:Button ID="Button1" runat="server" Text="Button" />

                </ContentTemplate>
            </asp:UpdatePanel>
        </div>
    </form>

    <script src="js/tooltip.js"></script>

I have tried to write/append the js path but its not working * I don`t have to call the function directly.

Any help will be appreciated.. Thanks