string[] t = textBox2.Text.Split('\n');
             listBox1.Items.Add("Прочитано прокси серверов: " + t.Length.ToString());
             foreach (string t1 in t)
             {
                 if (t1 != "" && t1.Contains(":"))
                 {
                     string[] t2 = t1.Split(':');
                     listBox1.Items.Add("Смена прокси сервера на: " + t1);
                     Proxy.Set(new WebProxy(t2[0], Convert.ToInt32(t2[1])));  
                     listBox1.Items.Add("Прокси сервер: " + t1 + "успешно установлен");
                     listBox1.Items.Add("Загрузка URL: " + textBox1.Text);
                     webBrowser1.Navigate(textBox1.Text);
                     while (webBrowser1.ReadyState != WebBrowserReadyState.Complete)
                     {
                         Application.DoEvents();
                     }
                     try
                     {

                         if (textBox4.Text == "Id")
                         {
                             listBox1.Items.Add("Поиск кнопки по Id: " + textBox3.Text);
                             webBrowser1.Document.GetElementById(textBox3.Text).InvokeMember("Click");
                             listBox1.Items.Add("Кнопка успешно нажата");
                             this.Refresh();
                         }
                         if (textBox4.Text == "Name")
                         {
                             listBox1.Items.Add("Поиск кнопки по Name: " + textBox3.Text);
                             HtmlElementCollection elmCol;
                             elmCol = webBrowser1.Document.Body.GetElementsByTagName("button");

                             foreach (HtmlElement elm in elmCol)
                             {
                    if (elm.GetAttribute("name") == textBox3.Text)
                    {
                    elm.InvokeMember("Click");
                    }
                             }
                             listBox1.Items.Add("Кнопка успешно нажата");
                             this.Refresh();
                         }
                         if (textBox4.Text == "Class")
                         {
                             listBox1.Items.Add("Поиск кнопки по Class: " + textBox3.Text);
                             HtmlElementCollection elmCol;
                             elmCol = webBrowser1.Document.GetElementsByTagName("button");

                             foreach (HtmlElement elmBtn in elmCol)
                             {
                    if (elmBtn.GetAttribute("className") == textBox3.Text)
                    {
                    elmBtn.InvokeMember("Click");
                    }
                             }
                             listBox1.Items.Add("Кнопка успешно нажата");
                             this.Refresh();
                         }
                     }
                     catch
                     {
                         listBox1.Items.Add("Ошибка поиска кнопки");
                     }
                 }
             }

internal static class Proxy
     {
         #region //wininet Interop
         private enum MyOptions
         {
             INTERNET_PER_CONN_FLAGS = 1,
             INTERNET_PER_CONN_PROXY_SERVER = 2,
             INTERNET_PER_CONN_PROXY_BYPASS = 3,
             INTERNET_PER_CONN_AUTOCONFIG_URL = 4,
             INTERNET_PER_CONN_AUTODISCOVERY_FLAGS = 5,
             INTERNET_OPTION_REFRESH = 37,
             INTERNET_OPTION_PER_CONNECTION_OPTION = 75,
             INTERNET_OPTION_SETTINGS_CHANGED = 39,
             PROXY_TYPE_PROXY = 0x00000002,
             PROXY_TYPE_DIRECT = 0x00000001
         }
         private enum ROptions
         {
             INTERNET_PER_CONN_FLAGS = 1,
             INTERNET_PER_CONN_PROXY_SERVER = 2,
             INTERNET_PER_CONN_PROXY_BYPASS = 3,
             INTERNET_PER_CONN_AUTOCONFIG_URL = 4,
             INTERNET_PER_CONN_AUTODISCOVERY_FLAGS = 5,
             INTERNET_PER_CONN_AUTOCONFIG_SECONDARY_URL = 6,
             INTERNET_PER_CONN_AUTOCONFIG_RELOAD_DELAY_MINS = 7,
             INTERNET_PER_CONN_AUTOCONFIG_LAST_DETECT_TIME = 8,
             INTERNET_PER_CONN_AUTOCONFIG_LAST_DETECT_URL = 9,
             INTERNET_OPTION_REFRESH = 37,
             INTERNET_OPTION_PER_CONNECTION_OPTION = 75,
             INTERNET_OPTION_SETTINGS_CHANGED = 39,
             INTERNET_OPTION_PROXY = 38,
             INTERNET_OPEN_TYPE_PROXY = 3
         }
         [Flags]
         private enum Flags
         {
             PROXY_TYPE_DIRECT = 0x00000001, //Интернет доступ через прямое соединение(без прокси)
             PROXY_TYPE_PROXY = 0x00000002, //Интернет доступ используя прокси
             PROXY_TYPE_AUTO_PROXY_URL = 0x00000004,
             PROXY_TYPE_AUTO_DETECT = 0x00000008
         }
         [Flags]
         private enum ProxyFlags
         {
             AUTO_PROXY_FLAG_USER_SET = 0x00000001,
             AUTO_PROXY_FLAG_ALWAYS_DETECT = 0x00000002,
             AUTO_PROXY_FLAG_DETECTION_RUN = 0x00000004,
             AUTO_PROXY_FLAG_MIGRATED = 0x00000008,
             AUTO_PROXY_FLAG_DONT_CACHE_PROXY_RESULT = 0x00000010,
             AUTO_PROXY_FLAG_CACHE_INIT_RUN = 0x00000020,
             AUTO_PROXY_FLAG_DETECTION_SUSPECT = 0x00000040
         }
         [StructLayout(LayoutKind.Explicit, Size = 12)]
         private struct INTERNET_PER_CONN_OPTION
         {
             [FieldOffset(0)]
             public int dwOption;
             [FieldOffset(4)]
             public int dwValue;
             [FieldOffset(4)]
             public IntPtr pszValue;
             [FieldOffset(4)]
             public IntPtr ftValue;
             public byte[] GetBytes()
             {
                 byte[] b = new byte[12];
                 BitConverter.GetBytes(dwOption).CopyTo(b, 0);
                 switch (dwOption)
                 {
                     case (int)MyOptions.INTERNET_PER_CONN_FLAGS: BitConverter.GetBytes(dwValue).CopyTo(b, 4);
                         break;
                     case (int)MyOptions.INTERNET_PER_CONN_PROXY_BYPASS: BitConverter.GetBytes(pszValue.ToInt32()).CopyTo(b, 4);
                         break;
                     case (int)MyOptions.INTERNET_PER_CONN_PROXY_SERVER: BitConverter.GetBytes(pszValue.ToInt32()).CopyTo(b, 4);
                         break;
                 }
                 return b;
             }
         }
         [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
         private class INTERNET_PER_CONN_OPTION_LIST
         {
             public int dwSize;
             public string pszConnection;
             public int dwOptionCount;
             public int dwOptionError;
             public IntPtr pOptions;
         }
         [StructLayout(LayoutKind.Sequential)]
         private struct INTERNET_PROXY_INFO
         {
             public int dwAccessType;
             public IntPtr lpszProxy;
             public IntPtr lpszProxyBypass;
         }
         private const int ERROR_INSUFFICIENT_BUFFER = 122;
         private const int INTERNET_OPTION_PROXY = 38;
         private const int INTERNET_OPEN_TYPE_DIRECT = 1;
         private const int INTERNET_OPEN_TYPE_PROXY = 3;
         [DllImport("wininet.dll", SetLastError = true)]
         private static extern bool InternetSetOption(IntPtr hInternet, int dwOption, INTERNET_PER_CONN_OPTION_LIST lpBuffer, int dwBufferLength);
         [DllImport("wininet.dll", SetLastError = true)]
         private static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int lpdwBufferLength);
         [DllImport("kernel32.dll")]
         private static extern int GetLastError();
         #endregion
         public static bool Set(WebProxy wProxy)
         {
             try
             {
                 bool bReturn = false;
                 INTERNET_PROXY_INFO info = new INTERNET_PROXY_INFO();
                 string sPrx = "";
                 if (wProxy != null)
                 {
                     sPrx = wProxy.Address.DnsSafeHost + ":" + wProxy.Address.Port;
                     info.dwAccessType = INTERNET_OPEN_TYPE_PROXY;
                 }
                 else
                 {
                     info.dwAccessType = INTERNET_OPEN_TYPE_DIRECT;
                 }
                 info.lpszProxy = Marshal.StringToHGlobalAnsi(sPrx);
                 info.lpszProxyBypass = Marshal.StringToHGlobalAnsi("rado.ra-host.com");
                 IntPtr intptrStruct = Marshal.AllocCoTaskMem(Marshal.SizeOf(info));
                 Marshal.StructureToPtr(info, intptrStruct, true);
                 bReturn = InternetSetOption(IntPtr.Zero, INTERNET_OPTION_PROXY, intptrStruct, Marshal.SizeOf(info));
                 bReturn = InternetSetOption(IntPtr.Zero, (int)MyOptions.INTERNET_OPTION_REFRESH, IntPtr.Zero, 0);
                 Marshal.FreeCoTaskMem(intptrStruct);
                 return bReturn;
             }
             catch (Exception)
             {
                 throw;
             }
         }

     }