You need to add the following references to build it
successfully.
1.
System.Design
2.
System.Drawing
3.
System.Web
4.
System.Web.Extensions
5.
System.Web.Extensions.Design
As you see in Listing 1, our custom control will inherit the
CompositeControl class and it has an “asp” prefix tag
to make our custom control supporting Intellisense in the HTML view source.
Keep in mind that if you are using Visual Studio 2005, you
have to install at least Visual Studio 2005 SP1 to fix the Intellisense bug.
Listing 1
Namespace CustomsControls
< _
AspNetHostingPermission(SecurityAction.Demand, _
Level
= AspNetHostingPermissionLevel.Minimal), _
AspNetHostingPermission(SecurityAction.InheritanceDemand, _
Level
= AspNetHostingPermissionLevel.Minimal), _
Designer(GetType(MultiLangDesginTime)), _
ToolboxData("<{0}:CustomMultiLang runat=""server"" />") _
> _
Public Class CustomMultiLang
Inherits CompositeControl
End Class
End Namespace 
