The Save File, User Defined Function Key described above has a danger. This danger illustrates the perils of programming at all levels. No matter how innocuous a User Defined Function Key seems, you must consider all possible scenarios.
Suppose you start a new MEMO. After a few minutes you want to save the MEMO using our newly created User Defined Function Key. Don't do it! (Remember our User Defined Function Key was designed to replace an existing file.)
Here's what can happen: If our Save File, User Defined Function Key is used on a new file, MEMO will save the new file to the first MEMO file it finds in the MEMO directory. It overwrites that file, erasing its contents!
Let's try it by hand. Go into MEMO and press <MENU> File New. Now type "test file", press <MENU> File Save, and take a look at your screen. Notice that the cursor is highlighting the first file in your directory. Press <ENTER> and you are asked whether you want to "Replace current file? (Y/N)". You MUST answer N here to cancel the Save. If you enter Y, the file that was highlighted by the cursor will be replaced (gone forever) by the new (test file) file you just created!
I solve this problem by creating a meaningless file, one-word file and saved it as AAAAAAAA.TXT. This way, if I space out and use my Save File, User Defined Function Key to save a new MEMO, I have saved it into AAAAAAAA.TXT without writing over any other .TXT file.
The real point here is that User Defined Function Keys gives you more power by permitting a single keystroke combination to stand for a specific series of keys. But if that power is not used wisely, bad things can happen. In particular examine your User Defined Function Keys to see if they have the capability of destroying something, as our Save File example does. Then consider carefully the various possibilities in which the User Defined Function Key might delete a file, either purposefully or accidentally. Make adjustments accordingly. You are now thinking a little like a programmer.