DHTMLX Grid : Updating the changed data to JSON object and X

Hi,

I have a query that suppose I update or delete a row of data from grid then how to update the corresponding XML file if I am using XML file to load the grid and how to update JSON object if I am using JSON object to load the grid ?

then how to update the corresponding XML file
Grid can be serialized back to XML
    var xml=grid.serialize();
There is no similar functionality for JSON.