how to access usercontrol value in js/jquery

Suppose i created a user control which contain two textbox, one button

 --Start UserControl UserDetails--
 <asp:TextBox runat="server" id="txtName"></asp:TextBox>
 <asp:TextBox runat="server" id="txtAddress"></asp:TextBox>
--End UserControl UserDetails-

in aspx if i use the same user control,

<uc1:UserDetails runat="server" ID="UserDetails1" />

1. how do i access the txtName using user control id UserDetails1?
2. How do i make $('#UserDetails1').val() to return value of txtName?

Just add a public property for you TextBox in you user control code behind

public TextBox Name
{
    get { return txtName; }
    set { txtName = value; }
}

Now you can access your TextBox like this:

<uc1:UserDetails runat="server" ID="UserDetails1" />

    <script>
        $(function () {
            $("#<%= UserDetails1.Name.ClientID%>").val("set you text here");
            //or
            var name = $("#<%= UserDetails1.Name.ClientID %>").val();
        });
    </script>