> firebirdsql.jar
> log4j-core.jar

you do not need log4j-core.jar in classpath

> mini-j2ee.jar
> mini-concurrent.jar

> jass.jar
> firebirdjmx.jar
> firebirdsql-test.jar

these three are also not needed.

> in C:\calsoft\j2sdk\jre\lib\ext directory

move them to the tomcat's lib/ or webapps/yourapp/WEB-INF/lib

> My classpath is:-
> C:\calsoft\j2sdk\lib\servlet.jar;C:\calsoft\j2sdk\jre\lib
>
> Now i am trying to run my servlet i am getting an error
>
> class java.lang.ClassNotFoundException class
> java.lang.NullPointerException

If the recommendations above do not help, post complete stack trace
here.

> I want to know wheather any chnages needed at apachi server side.

nothing that i know.

best regards,
roman rokytskyy