Updating XML file data

["Mark A. Richman" <mr...@ispchannel.com>]

I have updated a node's value and I wish to write the tree back out to the file I read it from.  What is the easiest way to do this?  Also, if multiple users will be doing this simultaneously, will an IOException get thrown, or will the caller get blocked until the XML file becomes available for writing?  If there are concurrency issues with this, I may have to put all my data in SQL, rather than XML.

Thanks,
Mark