see this example:

<form runat="server">
    <asp:Button runat="server" ID="btFoo" Text="asp.net button" />
    <button id="btFoo2">open modal</button>
    <script type="text/javascript">
        $(document).ready(function() {
            var btFoo = $('#<%= this.btFoo.ClientID %>');
            btFoo.click(); // this will work and cause a postback

            btFoo.click(function() {
                alert('click triggered');
            });

            var dialog = $('<div/>');
            dialog.text('please click yes');
            dialog.dialog({
                autoOpen: false,
                open: function() {
                    var widget = dialog.dialog('widget');
                    widget.appendTo($('form'));
                },
                buttons: {
                    'YES': function() {
                        btFoo.click(); // this will cause a click, but no postback??!!
                    }
                }
            });

            var btFoo2 = $('#btFoo2');
            btFoo2.click(function() {
                dialog.dialog('open');
                return false;
            });
        });
    </script>
</form>

any help would be appreciated, to get this example working!