我是初学者，一段程序如下

< %@Import Namespace=System.Data%>

< %@Import Namespace=System.Data.ADO%>
<Script Language="VB" Runat="Server">
Sub Page_Load (Sender As Object,E as EventArgs)
Dim cnA as ADOConnection =New ADOConnection

其余省略
程序编译时提示第五行出错，提示为Type "ADOConnection " is not defined.
请教各位错在哪儿呢？程序我是照书上抄的啊!谢谢各位。