need to create a back up ability for xml file used in a program

Question

hello all.

im making a program that edits XML as part of this i want it to have a back up ability.

so im looking for help in creating a copy of the XML file and saving it in an unused back up folder so if it get corrupted it can be copied back over to the working folder of the program. so im after saving the current working file as a back up and recovering the back up if the working file is damaged.
im using Visual studio 2008 in VB.net

i would be very thankful for any help Michael