C#访问网站

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace AccessWeb
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
HtmlElement tbUserid = webBrowser1.Document.All["email"];
HtmlElement tbPasswd = webBrowser1.Document.All["password"];
HtmlElement btnSubmit = webBrowser1.Document.All["action"];

if (tbUserid == null || tbPasswd == null || btnSubmit == null)
return;

tbUserid.SetAttribute("value", "[e-mail]");
tbPasswd.SetAttribute("value", "testtest");
btnSubmit.InvokeMember("value", "login");


}
}
}