data averaging

[T. Song]

Dear Dr. Oostenveld and Fieldtriper:

I am working on the sample data from MGH, which was obtained from a Neuromag
306 MEG machine, with 4 kinds of triggers. Would you please give me some
advice regarding averaging epochs? Which funciton should I use in Fieldtrip
toolbox?
BTW, how do I use definetrial? I read the help file, but am confused. Do you
have some example?

Thanks a lot!

T. Song