Is it possible to detect which proxy is active which is dead? using c# and a combo box containing list of proxies with port number is there any way we take every proxy one by one and determine as if it was dead or active?

 Microsoft.Win32.RegistryKey registry = Microsoft.Win32.Registry.CurrentUser.OpenSubKey("Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings", true);
                    registry.SetValue("ProxyEnable", 1);
                    registry.SetValue("ProxyServer", comboBox1.Text)

;