Open (Show) jQuery UI Dialog Modal Popup from Server Side with Master Page in ASP.Net

Here I have created sample,it is working fine with master page.

MasterPage

<div>
    <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
        *****Master page*****
    </asp:ContentPlaceHolder>
</div>

ChildPage

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
    <script src="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.9/jquery-ui.js" type="text/javascript"></script>
    <link href="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.9/themes/start/jquery-ui.css"
        rel="stylesheet" type="text/css" />
    <script type="text/javascript">
        function ShowPopup(message) {
            $(function () {
                $("#dialog").html(message);
                $("#dialog").dialog({
                    title: "jQuery Dialog Popup",
                    buttons: {
                        Close: function () {
                            $(this).dialog('close');
                        }
                    },
                    modal: true
                });
            });
        };
    </script>
    <div id="dialog" style="display: none">
    </div>
    <asp:Button ID="btnShowPopup" runat="server" Text="Show Popup" OnClick="btnShowPopup_Click" />
</asp:Content>

ChildPageCode

protected void btnShowPopup_Click(object sender, EventArgs e)
{
    string message = "Message from server side";
    ClientScript.RegisterStartupScript(this.GetType(), "Popup", "ShowPopup('" + message + "');", true);
}

Screenshot