rob,
don't you know the sct tables?
In the Navy they always taught us to remember that stuff with sentences.
Sally Can Tell Oscar Has A Harb On Again. (editted for family viewing)
Translates to:
S=O/H
C=A/H
T=O/A
Notice the pattern?
Clear as mud.

A word to the wise is not necessary. It is the stupid ones who need the advice. Pat