Question: How to add a legend to a plot?

Good morning everybody


I know this question has already been widely discussed, for example in
http://www.mapleprimes.com/questions/149585-How-To-Order-Legend-Of-Multiple-Plots

I used the answer Kitonum then gave because I have basically the same kind of problem.
As an illustration, here is a sketch of my coding :

N := 3:
for k from 1 to N do
   ...
   MyPlot||k := PLOT(CURVES(....)):
   ...
end do:
plots:-display(seq(MyPlot||k, k=1..N));

The only difference is that I use PLOT instead of plot ... so I have thought that using LEGEND instead of legend would give me the desired result.
But I don't understand how to use LEGEND and how to place the legend in the correct location.

I will appreciate any answer,
Thanks in advance