Nadya,

>
>I have FileAdmin application. It basically logs files used in the system, allows to archive/unarchive them, delete them, etc.
>The main form has a grid and a standard navigation bar. If user presses delete button, selected records are deleted, some info in the record is updated and files get deleted too. However, form uses 5 buffering, which means, that user may regret his/her action and press a revert button.
>

If you don't use 5 buffering, then noone may have any regrets *grin*

>So, my question is: what would you suggest me to do? How can I find out, if record was deleted and then reverted back?

I don't understand this question...you know if the user hits the revert button, right?

>How can I undelete the file?

You could put the file in the recycle bin, but then it is on local machine. Another (better) option is this: instead of deleting the file, move it to a "TrashCan" folder under your application data directory. If this system spans across different folders, with duplicate file names, you can give the file a temporary (unique) file name when it goes to the TrashCan, and store this new file name in a field in your file manager.

Have a routine periodically clear out the TrashCan with time stamps older than a certain date, or have the files deleted from the TrashCan when the user hits the "I really mean it" button.