Setting legends for multiple graphs

Hi, I have this set of plots now and i want to set a legend for all these graphs. Is there any way of doing so. All these plots are generated by a single plot command for each iteration of offered traffic. So then how can i set the legend for it in this way?

Brown-15 Erlang.

Red-12 Erlang.

Yellow-10 Erlang.

. . Green-1 Erlang

Answer 1

[Azzi Abdelmalek]

legend({'leg1','leg2','leg3','leg4'})

[Aftab Ahmed Khan]

Thank you.