when I click one button and then showModalDialog wjhen I close this modaldialog window,the RadAjaxLoadingPanl appear。I don't want it to appear.
I set this in masterPage but it no use
<telerik:AjaxSetting AjaxControlID="button">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="RadAjaxLoadingPanel1" />
                </UpdatedControls>
            </telerik:AjaxSetting>

In content page :
<td style="width: 500px; height: 30px;">
                                                        <telerik:RadAjaxPanel ID="rapText" runat="server">
                                                            <telerik:RadComboBox ID="rcbText" runat="server" Width="493px" Style="height: auto;"
                                                                MarkFirstMatch="true" OnLoad="rcbText_Load" EnableLoadOnDemand="true" EmptyMessage="documentSelectionListBox "
                                                                AutoPostBack="True" OnSelectedIndexChanged="rcbText_SelectedIndexChanged"
                                                                Skin="WebBlue" MaxHeight="100px">
                                                            </telerik:RadComboBox>
                                                        </telerik:RadAjaxPanel>
                                                    </td>
                                                    <td>
                                                        <asp:Button ID="button" runat="server" Style="width: 75px; text-align: center; height: 25px;" Text="btnText" />
                                                    </td>

 function showPage() {
                var result = window.showModalDialog("Text.aspx", "", "dialogWidth:400px;dialogHeight:" + dialogheight + "px;toolbar=no,title:no;location=no;scroll:no;status:no;menubar=no;resizable:no;");
                var s = document.getElementById("<%=txtText.ClientID %>");
                s.Text = result;
                $find("<%=rapText.ClientID %>").ajaxRequest("ctl00_ContentPlaceHolder1_button");
            }
content code behind
this.button.Attributes.Add("onclick", "return showPage()");