Multihandleslider control not working in ajax?

hello  sir i want to use multihandleslider but this control not working in my page this control not move  so where is the problem?

here is my code

aspx

<div>

<asp:ScriptManager runat="server" ID="ToolkitScriptManager1"></asp:ScriptManager>



<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<asp:TextBox ID="txtSlider" runat="server" Width="40px"></asp:TextBox>

<ajaxToolkit:MultiHandleSliderExtender ID="MultiHandleSliderExtender2" runat="server" TargetControlID="txtSlider"
BehaviorID="multiHandleSliderOne"
Minimum="0"
Maximum="100"
Steps="80"
Length="317"
HandleAnimationDuration="0.1">
<MultiHandleSliderTargets>
<ajaxToolkit:MultiHandleSliderTarget ControlID="TextBox1" />
<ajaxToolkit:MultiHandleSliderTarget ControlID="TextBox2" />
</MultiHandleSliderTargets>
</ajaxToolkit:MultiHandleSliderExtender>

</div>