Save changes of a Custom Editor when save button clicked

I have written a plugin to create the archives and its implmented as a new editor. this editor is a UI and it doesnot directly write the content to the file. it has drop down boxes, text boxes etc, and the values selected are stored in a file, in XML format.

I want to save the changes up on the clickin gon save button, can any body help me on this.

thanks in advance

Ruwan