ASP强人、版主进（很着急）

错误类型：
Microsoft OLE DB Provider for ODBC Drivers (0x80004005)
[Microsoft][ODBC 驱动程序管理器] 未发现数据源名称并且未指定默认驱动程序
/a/include/cod_ado.inc, 第 4 行
COD_ADO.INC源代码是
<%
sub cod_AdoOpen(objConnection,rsCoursesList,dsn,rss)
    Set objConnection = Server.CreateObject("ADODB.Connection")
    objConnection.Open dsn
    Set rsCoursesList = Server.CreateObject("ADODB.Recordset")
    rsCoursesList.ActiveConnection =objConnection    
    rsCoursesList.CursorLocation =adUseClient
    rsCoursesList.CursorType =adOpenForwardOnly
    rsCoursesList.LockType =adLockReadOnly
    rsCoursesList.Source =rss
    rsCoursesList.Open
end sub
sub cod_AdoClose(objConnection, rsCoursesList)
    rsCoursesList.close
    objConnection.close
    set rsCoursesList = nothing
    set objConnection = nothing
end sub
%>有请各位高手帮忙解决，谢谢