You can add a Timer object with the time span you need (let's say one minute) and get the XML again BUT you most probably face a caching problem where the XML contents will remain the same because the XML name didn't change.
There are 2 options for that. First, rename the XML (or add a parameter to its filename) but this option s valid only if you can administer the server or disable http caches in your code and cross your fingers to succeed because it's not always possible to persuade server with this.
A sample of what you need can be found here
http://stackoverflow.com/questions/4...shot-test-code