登录后default.aspx页面无法打开.

Imports System.Data.SqlClient.SqlConnection
Imports System.Data.SqlClient

Public Class login11
    Inherits System.Web.UI.Page
    Public Function Validate_Login(ByVal Username As String, ByVal Password As String) As Integer

        Dim con As SqlConnection = New SqlConnection("Data Source=KARANDE\sqlexpress;Initial Catalog=nitink;Integrated Security=True")
        Dim cmdselect As SqlCommand = New SqlCommand()
        cmdselect.CommandType = CommandType.StoredProcedure
        cmdselect.CommandText = "[dbo].[Log_prcLog]"

        cmdselect.Parameters.AddWithValue("@Username", Username)
        cmdselect.Parameters.AddWithValue("@UPassword", Password)
        cmdselect.Parameters.AddWithValue("@OutRes", SqlDbType.Int)



        '   cmdselect.Parameters.Add("@Username", SqlDbType.VarChar, 50).Value = Username
        ' cmdselect.Parameters.Add("@UPassword", SqlDbType.VarChar, 50).Value = Password
        'cmdselect.Parameters.Add("@OutRes", SqlDbType.Int, 4)
        cmdselect.Parameters("@OutRes").Direction = ParameterDirection.Output
        cmdselect.Connection = con
        Dim Results As Integer = 0
        Try
            con.Open()
            cmdselect.ExecuteNonQuery()
            Results = CType(cmdselect.Parameters("@OutRes").Value, Integer)
        Catch ex As SqlException
            lblMessage.Text = ex.Message
        Finally
            cmdselect.Dispose()
            If Not con Is Nothing Then
                con.Close()
            End If
        End Try
        Return Results
    End Function

    Protected Sub btnlogin_Click(sender As Object, e As EventArgs)
        Dim Results As Integer = 0
        If txtUsername.Text <> String.Empty AndAlso txtPassword.Text <> String.Empty Then
            Results = Validate_Login(txtUsername.Text.Trim(), txtPassword.Text.Trim())


            If Results = 1 Then
                lblMessage.Text = "Login is Good, Send the User to another page or enable controls"
            Else
                lblMessage.Text = "Invalid Login"
                lblMessage.ForeColor = System.Drawing.Color.Red

            End If
        Else
            lblMessage.Text = "Please make sure that the username and the password is Correct"
        End If

    End Sub

End Class