public partial class WebBrowserForm : Form
    {
        public WebBrowserForm()
        {
            InitializeComponent();
        }

        private void btnLoad_Click(object sender, EventArgs e)
        {
            Previewer.Show();
            this.webBrowser1.Refresh();
            Previewer.Navigate("http://google.com");
        }

        private WebBrowser Previewer
        {
            get
            {
                if(webBrowser1 == null || webBrowser1.IsDisposed)
                {
                    //Controls.Remove(webBrowser1);

                    webBrowser1 = new WebBrowser();

                    //Controls.Add(webBrowser1);

                    this.webBrowser1.Location = new System.Drawing.Point(12, 12);
                    this.webBrowser1.MinimumSize = new System.Drawing.Size(20, 20);
                    this.webBrowser1.Name = "webBrowser1";
                    this.webBrowser1.Size = new System.Drawing.Size(776, 250);
                    this.webBrowser1.TabIndex = 0;
                    this.webBrowser1.Show();
                }

                return webBrowser1;
            }
        }

        private void btnDispose_Click(object sender, EventArgs e)
        {
            webBrowser1.Dispose();
        }
    }