Change in AppSettings needs restart my Application how can I avoid?

I'm using C# .NET 2.0 Windows Application.

and I'm using app.config for my Application Settings.

but change in AppSettings doesn't reflected runtime, it Needs Application to be restarted.

How can I avoid it.

Here is my code snippet I used to read and write the Application Settings.

I'm reading the Setting like this

string temp = ConfigurationManager.AppSettings.Get(key);

I'm updating the value like this where node is the current configuration/appSettings Node

node.Attributes["value"].Value = value;
xmlDoc.Save(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile);