YUI (YAHOO) blocking my UI when i show the panel

Question

i have a problem with this YUI modal , when i clic the button , it show the panel but is blocking the UI , and i cannot understand how to configure or prevent that behavior this is the code :

<asp:Button ID="RemoveEventButton" runat="server" OnClientClick="cancelEventPanel.show();return false;" CssClass="button" />

<script type="text/javascript">

    var cancelEventPanel;
    YAHOO.util.Event.onDOMReady(function() {
        cancelEventPanel = new YAHOO.widget.Panel('<%= RemoveEventPanel.ClientID %>', { visible: false, width: "325px", constraintoviewport: false, fixedcenter: true, draggable: false, modal: true, close: true });
        cancelEventPanel.render(document.forms[0]);

        cancelEventPanel.hideEvent.subscribe(function() {
            $('#<% = CancellationNotes.ClientID %>').val('').keyup();
        });
    });

    function cancelEventPopupClose() {
        cancelEventPanel.hide();
        return false;
    }

    </script>


<asp:Panel ID="RemoveEventPanel" runat="server" style="visibility:hidden;" CssClass="contactpanel">
        <div class="hd">
            <ctls:Content ID="Content2"  runat="server"/>
        </div>
        <div class="bd">
            <table class="formtable" style="width: 325px">
                <tr>
                    <td><ctls:Content ID="Content4" runat="server"/></td>
                </tr>
                <tr>
                    <td>
                        <ctls:TextArea ID="CancellationNotes" runat="server" MaxLength="250" Width="275" Rows="4" />
                    </td>
                </tr>
                <tr>
                    <td>
                        <ctls:Button ID="RemoveEventButton2" runat="server" OnClick="RemoveEventButton2_Click" CssClass="button" CausesValidation="true"/>
                        <ctls:Button ID="CancelEventButton" runat="server" CausesValidation="false" CssClass="button" OnClientClick="return cancelEventPopupClose();" />
                    </td>
                </tr>
            </table>
        </div>
    </asp:Panel>    

Answer 1

Change the modal property to false.