Labeling contour lines in surface plots?

[Kristen]

Hello,

I have plotted the contour lines illustrating the combinations of various
reinforcing bars necessary to achieve a desired steel area. The contour plot
looks great, and it's fairly clear. However, I'd like to label the isolines
(i.e., As = 1 in2), and have not been able to figure out how to do this yet.
I've adjusted the chart style to show the lines (as well as the x- and y-
axis gridlines), but I cannot figure out how to label the lines.

Any help would be appreciated!

Thanks!