Dear pra,
Safe zone stop method is invented by Alexander Elder & his student in his book trading for living, the basic concept is how to trail your stops and avoid your position getting frequently stopped out by smart operators.
How i use it in practice as shown above? well SZ gives a figure before hand, at right age of the chart if ur short then sz stop is 2897.04 ( its just illustration as market has been closed so i dont count that fig.) as per saints flow method i wd reverse to long after crack of pivot but suppose new pivot formed at 2920 then instead of waiting i will cover my part positions at sz stop 2897.04. ( again,its just an example, actually i use 15 min tf and book my part positions as per sz stops ). Same apply for sz stops for long, which is now 2845.15 ( in red font ).
Its practical application is only useful for setting trailing stoplosses and try to maintain remain in flow.
Hope it clears
Alex
p.s. about using afl file as pra said unzip with the help of free application winrar, then save that file in c<programs<amibroker<formulas<custom
then restart amibroker, n u will find that afl out there under charts<custom now left click on that afl and drag it on the main chart and done.