Birt Report Error

Hello,
I am trying to add a birt report and display that report using the birt report viewer in my existing web application. I have modified the web.xml and copied the required birt components from a working stand alone BIRT web project into my webapp. Please let me know whats causing the following error when I try to run the report:-

javax.servlet.ServletException: Servlet execution threw an exception
org.eclipse.birt.report.filter.ViewerFilter.doFilter(Unknown Source)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

root cause

java.lang.OutOfMemoryError: PermGen space
java.lang.ClassLoader.defineClass1(Native Method)
java.lang.ClassLoader.defineClass(Unknown Source)
java.security.SecureClassLoader.defineClass(Unknown Source)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1817)
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:872)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1325)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
java.lang.ClassLoader.loadClassInternal(Unknown Source)
org.eclipse.birt.report.model.parser.ModuleState$DataSourcesState.startElement(ModuleState.java:156)
org.eclipse.birt.report.model.parser.ModuleParserHandler.startElement(ModuleParserHandler.java:189)
org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
javax.xml.parsers.SAXParser.parse(Unknown Source)
org.eclipse.birt.report.model.parser.ModuleReader.readModule(ModuleReader.java:95)
org.eclipse.birt.report.model.parser.DesignReader.read(DesignReader.java:90)
org.eclipse.birt.report.model.core.DesignSession.openDesign(DesignSession.java:316)
org.eclipse.birt.report.model.api.SessionHandle.openDesign(SessionHandle.java:292)
org.eclipse.birt.report.engine.parser.ReportParser.getDesignHandle(ReportParser.java:158)
org.eclipse.birt.report.engine.api.impl.ReportEngineHelper.openReportDesign(ReportEngineHelper.java:243)
org.eclipse.birt.report.engine.api.impl.ReportEngine.openReportDesign(ReportEngine.java:484)
org.eclipse.birt.report.service.ReportEngineService.openReportDesign(Unknown Source)
org.eclipse.birt.report.utility.BirtUtility.getRunnableFromDesignFile(Unknown Source)
org.eclipse.birt.report.context.ViewerAttributeBean.getDesignHandle(Unknown Source)
org.eclipse.birt.report.context.ViewerAttributeBean.__init(Unknown Source)
org.eclipse.birt.report.context.BaseAttributeBean.init(Unknown Source)