[R] Post-hoc t-tests in 2-way repeated measure ANOVA

[Giuseppe Pagnoni]

Hi all

I am running a 2-way repeated measure anova with 1 between-subjects 
factor (Group=treatment, control), and 1 within-subject factor (Time of 
measurement: time1, time2).  I extract the results of the anova with:

summary(aov(effect ~ Group*Time + Error=Subj/Time, data=mydata))

Now, this must be clearly a dumb question, but how can I quickly extract 
in R all the post-hoc t-tests for the simple main effects?

Also, while I am at it, how do I enter in the model a counfounding 
covariate (e.g., Age)?

And on a different matter, is there a way to receive interactive user 
input in an R script? Something like "Enter the name of  the factor:  ", 
or even more simply "Press <Enter> to see the result of the next 
analysis"....

thanks in advance for any suggestions!

    giuseppe

-- 
------------------------
Giuseppe Pagnoni, Ph.D.
Dept. of Psychiatry and Behavioral Sciences
1639 Pierce Drive, Suite 4000
WMB Bldg., Atlanta, GA 30322, U.S.
phone: 404-712-8431
fax: 404-727-3233
e-mail: gpagnon at emory.edu