Error while generating XML in Tomcat

[Manish Hatwalne]

I am generating XML dynamically from my servlet. When program is run as a
stand alone, it generates XML properly, but when I am using it as a servlet
in Tomcat 4.0.4, it generates error - NoClassDefFoundError. I have JDK 1.4
installed on my macine, do I need to specify sth explicitly in Tomcat
classpath or something...
I am lost, any help would be highly appreciated.

The error log -

java.lang.NoClassDefFoundError: org/xml/sax/ext/Attributes2
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:509)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
at
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLo
ader.java:1643)
at
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.jav
a:937)
at
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.jav
a:1372)
at
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.jav
a:1254)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:322)
at gnu.xml.aelfred2.XmlReader.(XmlReader.java:67)
at gnu.xml.aelfred2.JAXPFactory$JaxpParser.(JAXPFactory.java:140)
at gnu.xml.aelfred2.JAXPFactory.setFeature(JAXPFactory.java:98)
at gnu.xml.dom.JAXPFactory.newDocumentBuilder(JAXPFactory.java:96)
at TransitionServlet.getXML(TransitionServlet.java:127)
at TransitionServlet.doGet(TransitionServlet.java:60)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:247)

TIA,
- Manish