getting error of java.lang.NullPointerException

I am getting error of java.lang.NullPointerException.

Previously I used Tomcat 4.0 and my code is working fone...

but when I upgraded my tomcat 4.0 to tomcat 6.0 it gives me the error of java.lang.NullPointerException.

Please help me ....
it gives error of on line
int id = Integer.parseInt(cachedRS.getString("SerialNo"));

Step one is to move the Java code out of the JSP and into a controller of bean class so that it follows best practices and is easier to debug.