Error while deploying chartEngine on webApplication

mann

Hi,
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

java.lang.NullPointerException
org.eclipse.emf.ecore.xmi.impl.XMLLoadImpl.getEncoding(XMLLoadImpl.java:319)
org.eclipse.emf.ecore.xmi.impl.XMLLoadImpl.load(XMLLoadImpl.java:124)
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)
ChartRenderingServlet.doPost(ChartRenderingServlet.java:185)
javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

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......

thanks mann