[R] dotPlot with diagonal

[Jörg Reuter]

Hi,
I want draw a dotPlot. All works fine:
(Seq <- matrix(c(1, 1, 6, 1, 2, 2, 5, 4, 3, 3, 4, 3,
4, 4, 3, 2, 5, 5, 2, 5, 6, 6, 1, 6), ncol = 6))
dotPlot(Seq[1,], Seq[2,], main = "Sequenz 1 und
Sequenz 2", asp = 1)
Is there a way to draw a small diagonal, begin at (0/0) to (6/6)
(perhaps in red??) or must I use gimp? I have many dotPlots, so it is
fine if R can do this.

Thanks Joerg