Hi Mana,
It looks like you want to do some version of your project.
Then, I would recommend using CVS (which is a version control tool integrated in KDS).
please search it in "Help" of KDS for detail information!
by the way, KDS also provide a "compare" feature to compare you source code with history.
By just right click in your source code and then "Compare with" to launch it!
hope it helps!