Getting a runtime exception while deploying app.

[deepsix]

Hi, apologies if the question is silly..
I am new to seam and trying to create my own application using seam. .
Whenever i deploy the application, i get the following runtime exception..
Any ideas what jar i am missing referring to?
exception

javax.servlet.ServletException: Servlet execution threw an exception
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

root cause

java.lang.NoClassDefFoundError: org/jboss/el/lang/EvaluationContext
org.jboss.seam.jsf.SeamApplication.getExpressionFactory(SeamApplication.java:346)
com.sun.facelets.compiler.Compiler.createExpressionFactory(Compiler.java:131)
com.sun.facelets.impl.DefaultFaceletFactory.createFacelet(DefaultFaceletFactory.java:198)
com.sun.facelets.impl.DefaultFaceletFactory.getFacelet(DefaultFaceletFactory.java:144)
com.sun.facelets.impl.DefaultFaceletFactory.getFacelet(DefaultFaceletFactory.java:95)
com.sun.facelets.FaceletViewHandler.buildView(FaceletViewHandler.java:517)
com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:567)
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:106)
com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:144)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:245)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

[deepsix]

As expected, i didnt put in the jboss-el.jar in the classpath of the ejb and the webapp.