A test program, perfect in Earlier Version, but not 9. The problem is, how to do it with Mathematica 10 or 9?
Needs["PlotLegends"] g1 = Plot[Sin[x], {x, 0, 2 Pi}]; legend = Join[{Graphics[{Thick, Blue, Dashed, Line[{{0, 2}, {15, 2}}]}], #1} & @@@ {{Style[ "\[CapitalOmega]=15", FontSize -> 11, FontFamily -> "Times New Roman"]}}, {Graphics[{Thick, Red, Dotted, Line[{{0, 2}, {15, 2}}]}], #1} & @@@ {{Style[ "\[CapitalOmega]=20", FontSize -> 11, FontFamily -> "Times New Roman"]}}, {Graphics[{Thick, Black, DotDashed, Line[{{0, 2}, {6, 2}}]}], #1} & @@@ {{Style[ "\[CapitalOmega]=30", FontSize -> 11, FontFamily -> "Times New Roman"]}}, {Graphics[{Thick, Black, Dashed, Line[{{0, 2}, {6, 2}}]}], #1} & @@@ {{Style[ "\[CapitalOmega]=40", FontSize -> 11, FontFamily -> "Times New Roman"]}}]; ShowLegend[ Show[g1], {legend, LegendPosition -> {0.5
, 0.25}, LegendSize -> {0.5
, 0.4`}, LegendShadow -> None, LegendBorder -> None}]