ConfigurationManager save

public static class CString
{
/// <summary>
/// Returns an application setting based on the passed in string
/// used primarily to cut down on typing
/// </summary>
/// <param name="Key">The name of the key</param>
/// <returns>The value of the app setting in the web.Config
// or String.Empty if no setting found</returns>
public static string AppSetting(this string Key)
{
string ret = string.Empty;
if (System.Configuration.ConfigurationManager.AppSettings[Key] != null)
ret = ConfigurationManager.AppSettings[Key];
return ret;
}

public static void AppSetting(this string Key,string Value)
{
string ret = string.Empty;
if (System.Configuration.ConfigurationManager.AppSettings[Key] != null)
{
//Create the object
Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

config.AppSettings.Settings[Key].Value = Value;
config.Save(ConfigurationSaveMode.Modified);
ConfigurationManager.RefreshSection("appSettings");
}

}