How to type "Alt" key on Mac?

["jingzhao.ou" <jingzhao ou gmail com>]

Hi,

I have been using Dia on Windows and I love it very much.

Recently, I need to use it on Mac as well. However, I don't know how
to type short-cuts like "Shift-Alt-L" on Mac. I tried the "alt Option"
key but no luck. Can any one give me some hints?

Thanks a lot!
Jingzhao