Open database connection pool in Tomcat

Hi, who's has experience to open connection pool in Tomcat 5.5 using JNDI?
I recently research on it, i found the how-to guideline provided from apache tomcat website. It seem like not really work and i saw some of article they also encounter same issue as me.
if i put the datasource in context.xml then immediately the Tomcat not working. If you put it in the server.xml then it unable detect the datasource.

I has success open database connection in common dbcp method but i'm trying open it in JNDI.
Who's know how to open database connection pooling in JNDI? Can you share it to me? Thank (I'm using Informix database)

re: Open database connection pool in Tomcat

What you tried, show us the code. Only then we able to configure your problem.