连接SQL2005的问题！

Imports System.Data.SqlClient

   Dim myConnection As SqlConnection
   Dim myCommand As SqlCommand
   Dim dr As SqlDataReader

   Sub ConnectDataBase()
        Try
            myConnection = New SqlConnection("server=CHENGXU_PC\SQLEXPRESS;uid=;pwd=;database=Mail")
            myConnection.Open()
            myCommand = New SqlCommand("Select * from Mailfilter", myConnection)
            dr = myCommand.ExecuteReader
            Do
                While dr.Read()
                    Console.WriteLine(dr(0))
                    Console.WriteLine(dr(1))
                End While
            Loop While dr.NextResult()
        Catch
        End Try
        dr.Close()                '此处报错       
    myConnection.Close()
    End Sub

数据库登陆的方式是windows验证，用户名和密码都是灰色的



运行后报错




连接数据库采用的是的方法
请问怎么解决这个错误