Juice UI asp.net webforms adding via code behind -

i'd integrate spinner asp.net app have. dynamically render controls based on database records , via code behind. i'm having issues adding spinner in test project in vs 2012

        label iknowwhatiknow = new label();         iknowwhatiknow.associatedcontrolid = "_text";         iknowwhatiknow.text = "asp.net textbox";         iknowwhatiknow.id = "_text";          juice.spinner mine1 = new juice.spinner();         mine1.id ="_textspinner";         mine1.targetcontrolid = "_text";          mine1.autopostback = true;          placeholder1.controls.add(iknowwhatiknow);         placeholder1.controls.add(mine1);  

i get

extender control '_textspinner' cannot extend '_text'. extender controls of type 'juice.spinner' cannot extend controls of type 'system.web.ui.webcontrols.label'.

seems pretty straightforward, need choose targetcontrolid resolves besides label, this:

<asp:label id="_label" associatedcontrolid="_text" text="asp.net textbox" runat="server" />  <asp:textbox id="_text" runat="server" /> <juice:spinner targetcontrolid="_text" id="_textspinner" runat="server" autopostback="true"/>  <br/><br/>  <label for="_content__input">html input</label> <input type="text" id="_input" runat="server"/> <juice:spinner targetcontrolid="_input" id="_inputspinner" runat="server"/>