I m new to BIRT Chart .I m able to deploy chart Engine in java Application .
Now I m trying for a webApplication ,I got one Sample Example
but i m getting this error

type Exception report
description The server encountered an internal error () that prevented it from fulfilling this request.

exception java.lang.NullPointerException org.eclipse.emf.ecore.xmi.impl.XMLLoadImpl.getEncoding(XMLLoadImpl.java:320) org.eclipse.emf.ecore.xmi.impl.XMLLoadImpl.load(XMLLoadImpl.java:125) org.eclipse.emf.ecore.xmi.impl.XMLResourceImpl.doLoad(XMLResourceImpl.java:179) org.eclipse.emf.ecore.resource.impl.ResourceImpl.load(ResourceImpl.java:1094) org.eclipse.birt.chart.model.impl.SerializerImpl.read(SerializerImpl.java:234) ChartModels.loadChart(ChartModels.java:64) ChartRenderingServlet.doGet(ChartRenderingServlet.java:145) javax.servlet.http.HttpServlet.service(HttpServlet.java:690) javax.servlet.http.HttpServlet.service(HttpServlet.java:803) filters.ExampleFilter.doFilter(ExampleFilter.java:102)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.26 logs.

What should i do????
Is any body give me sm samples to create chart on web page and also
the description that whot to deploy it on Tomcat server with required jar files?????
pleas help me......