Telerik DropDown Dynamic popoulate (Cascading))

[Manne]

Hello,
I am having a rad scheduler (appointment) in that i am having one telerik dropdown in that i am having two values .
if i select any one value from present  telerik dropdown i need a new telerik dropdown in next line with out page loading (Means in one word Cascading present telerik drop down i need new telerik drop down) .
 i need this same concept at <telerik:radscheduler> when i click on list of appointments a pop up will be open.
In pop up i am using <telerik:radscheduler>
For more information i am enclosing  code and screen shot in that i need your concept with out page load.

<telerik:radscheduler id="MyRadSchedulerRD" runat="server" datakeyfield="ID" datastartfield="Start"
                                            advancedform-enablecustomattributeediting="true" datasubjectfield="Subject" daystarttime="08:00:00"
                                            dayendtime="21:00:00" timezoneoffset="00:00:00" datadescriptionfield="Description"
                                            dataendfield="End" width="800px" skin="Default" onappointmentcommand="RadScheduler1_AppointmentCommand"
                                            onformcreated="RadScheduler1_FormCreated" onappointmentupdate="RadScheduler_AppointmentUpdate"
                                            overflowbehavior="Expand" onclientappointmentediting="OnClientAppointmentEditing"
                                            startinsertinginadvancedform="true" datarecurrencefield="" onclienttimeslotclick="insertAppointment"
                                            onclientappointmentclick="editAppointment">
                                            <%--<AdvancedForm EnableResourceEditing="false" />--%>
                                             <AdvancedForm Modal="true"></AdvancedForm>                                             
                                             <WeekView HeaderDateFormat="dd/MM/yyyy"></WeekView>
                                            <AppointmentTemplate>
                                                <span><b>
                                                    <%# Eval("Subject") %>:&nbsp;</b></span><span style="font-style: italic;">
                                                        <%# Eval("Description") %></span>
                                                         <span style="font-style: italic;"></span>                                                                                                            
                                     
                                            </AppointmentTemplate>

                                          <%--   <ResourceTypes>
                                                                 <telerik:radcombobox id="ddAssigns" runat="server" width="200" height="200" emptymessage="Select User"
                                            datasourceid="ObjectDataSourceAssignedTo" datatextfield="OName" datavaluefield="AssignTo">
               </telerik:radcombobox>
                                             </ResourceTypes>--%>
                                             <ResourceTypes>
                                                <telerik:ResourceType KeyField="ViewATFlag" Name="Type*" TextField="ViewATFlagText" ForeignKeyField="ViewATFlag"
                                                    DataSourceID="ObjectDataSourceTypes" />
                                            </ResourceTypes>
                                              <ResourceTypes>
                                                <telerik:ResourceType KeyField="AssignTo" Name="Assigned To*" TextField="OName" ForeignKeyField="AssignTo"
                                                    DataSourceID="ObjectDataSourceAssignedTo" />
                                            </ResourceTypes>
                                            <ResourceTypes>
                                                <telerik:ResourceType KeyField="Apptype" Name="Property Type*" TextField="ResType" ForeignKeyField="Apptype"
                                                    DataSourceID="Propertytype" />
                                            </ResourceTypes>
                                            <ResourceTypes>
                                               <telerik:ResourceType KeyField="PropTo" Name="Sale*" TextField="OProp" ForeignKeyField="PropTo"
                                                    DataSourceID="ObjectDataSourcePropTo" />
                                            </ResourceTypes>
                                            <ResourceTypes>
                                               <telerik:ResourceType KeyField="PropTolet" Name="Letting*" TextField="OProplet" ForeignKeyField="PropTolet"
                                                    DataSourceID="ObjectDataSourcePropTolet" />
                                            </ResourceTypes>                                                              
                                                              
                                            <ResourceTypes>
                                                <telerik:ResourceType KeyField="ViewValFlag" Name="Flag" TextField="ResText" ForeignKeyField="ViewValFlag"
                                                    DataSourceID="ObjectDataSourceResource" />
                                            </ResourceTypes>          
                                            <ResourceTypes>
                                                <telerik:ResourceType KeyField="AppStatus" Name="Status*" TextField="ResText" ForeignKeyField="AppStatus"
                                                    DataSourceID="AppointmentTypesDataSource" />
                                            </ResourceTypes>
                                            <ResourceStyles>
                                                <telerik:ResourceStyleMapping Key="1" Text="Viewing" ApplyCssClass="rsCategoryBlue" />
                                                <telerik:ResourceStyleMapping Key="2" Text="Valuation" ApplyCssClass="rsCategoryRed" />
                                                <telerik:ResourceStyleMapping Key="3" Text="Follow Up" ApplyCssClass="rsCategoryGreen" />
                                            </ResourceStyles>                                                                                 
                                        </telerik:radscheduler>

 

and also once look over screen shot