R help - Feb 2012 - Some question about "rpart" and splitting criterion

Dear All,
I have questions about the function "rpart"  to construct a regression
tree in
R code.
My problem is how to change the splitting criteria.

In the "rpart" we have : parms=list(split="......") , I ask
you if in this
command is it possible to use an another splitting criterion to substitute the 
default criteria( gini or information)?

Does someone can help me ?
Thank you,
Myriam Tabasso