component context is not defined. Check tag syntax

I am using Struts 1.3.5 in Tomcat 5.5. I am trying to do the sample execrise on Tiles Framework, but I am encountering the following error
How to resolve this error? I have searched in google and couldn't find out the solution for it.

org.apache.jasper.JasperException: Error - tag.getAsString : component context is not defined. Check tag syntax
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
 
 
root cause 
 
javax.servlet.ServletException: Error - tag.getAsString : component context is not defined. Check tag syntax
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:843)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:776)
org.apache.jsp.Layout_jsp._jspService(Layout_jsp.java:106)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
 
root cause

Guys... Any help???