ScriptManager and CompareValidator issue

Hi,

  Do you know why the validation control does not work when I add  the asp:ScriptManager  tag? I use VS 2013 and the latest ajax installed using NuGet.

<asp:ScriptManager ID="ScriptManager1" runat="server">

</asp:ScriptManager>

<asp:TextBox ID="TextBox1" runat="server" ></asp:TextBox>
<asp:CompareValidator ID="CompareValidator1" runat="server" ControlToValidate="TextBox1" Operator="DataTypeCheck" Type="Integer" >Enter numeric values</asp:CompareValidator>

<asp:Button ID="Button1" runat="server" Text="Button" />

I saw the ToolkitScriptManager is not availabe now?

Thanks