ErrorMessage like Xml file used by the another process.Help Me Urgent

Question

I am updating some values and displaying data in my vb.net application

My problem is

 i want to store(write) the values in xml file and at the same time i want to get(read) the   xml file in web application 

At the same time i am accessing same xml file in both applications so i got 

ErrorMessage like Xml file used by the another process

Any way to access the same xml file for reading and writing with out error

Or any other method for transferring data from windows application to web application