Form1の全コード
using System;
using System.Windows.Forms;
namespace WebBrowser1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void TextBox1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                WebBrowser1.ScriptErrorsSuppressed = true;
                WebBrowser1.Navigate(TextBox1.Text);
            }
        }
        private void WebBrowser1_Navigated(object sender, WebBrowserNavigatedEventArgs e)
        {
            TextBox1.Text = WebBrowser1.Url.ToString();
            String Title = WebBrowser1.DocumentTitle;
        }
    }
}