How to save changes in propertygrid

Hi,

I have a class containing some properties. I am creating an object to that class and assigning to propertygrid. I will change the values of the properties. Now i want to save the changes in properties to a xml file.
How can i do this. I heard that propertybag class can help, but i don't know how to use it. Please any one of you help me.

Thank u in advance.
Bye,
Sree.