DirectJCo in Enterprise Application

hi all,

I created a Web Modele where servlet talking to R/3 using standalone JCo. But when I run the application, it gives com.sap.mw.jco.JCO is not found(ClassNotFoundException).

I added application reference as com.sap.mw.jco to application-j2ee.xml, it is working fine.

But now, it is not referring sapjco.rar instread to jrfc.rar

my question:

1) what is the difference using jrfc.jar & sapjco.jar other than performance?

2) how can I do the same with sapjco.jar (it is missing runtime reference)?

3) Do I need to deploy sapjco.jar separately or what?

thanks in anticipation,

nikhil