modal window not showing

Created by: medlag

Hi, I m trying to add a modal window to a page in visual studio 2012 (c# .net), the problem is when I click the show button nothing happens, I even copy-paste the exemple from the website and I got the same problem

this is the code:

<p><a href="#launch" class="btn btn-warning btn-large" data-toggle="modal">Contacter le donneur</a></p>
        <section id="launch" class="modal hide fade">
            <header class="modal-header">
                <h3>Contacter le donneur</h3>
                <asp:Button ID="btnExit" Text="X" runat="server" class="close" data-dismiss="modal" />
            </header>
            <div class="modal-body">
                <asp:Label ID="lbNm" runat="server">Votre Nom</asp:Label><br />
                <asp:TextBox ID="txtName" runat="server"></asp:TextBox><br />
                <asp:Label ID="lblMail" runat="server">Votre Email</asp:Label><br />
                <asp:TextBox ID="txtMail" runat="server"></asp:TextBox><br />
                <asp:Label ID="lblTel" runat="server">Votre Numero de Telephone</asp:Label><span style="color: #808080; font-size: 12px;"> (facultatif)</span><br />
                <asp:TextBox ID="txtTel" runat="server"></asp:TextBox><br />
                <asp:Label ID="lblText" runat="server">Votre Nom :</asp:Label><br />
                <asp:TextBox ID="txtText" runat="server" TextMode="MultiLine"></asp:TextBox>
            </div>
            <footer class="modal-footer">
                <asp:Button ID="btnSend" Text="Envoyer" runat="server" CssClass="btn btn-primary" />
            </footer>
        </section>