Error tag.getAsString:component context is not defined

[bbq]

When I run my application in Tomcat 5.0 I obtain this error:

Code:

2007-06-25 15:34:54 StandardWrapperValve[jsp]: Servlet.service()
javax.servlet.jsp.JspException: Error - tag.getAsString :
 component context is not defined. Check tag syntax
at org.apache.struts.taglib.tiles.GetAttributeTag.doEndTag(GetAttributeTag.java:157)
at org.apache.jsp.Layouts.myLayout_jsp._jspx_meth_til es_getAsString_0
(myLayout_jsp.java:146)
at org.apache.jsp.Layouts.myLayout_jsp._jspService(my Layout_jsp.java:74)
at org.apache.jasper.runtime.HttpJspBase.service(Http JspBase.java:94)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:802)
at org.apache.jasper.servlet.JspServletWrapper.servic 
e(JspServletWrapper.java:324)
at org.apache.jasper.servlet.JspServlet.serviceJspFil e(JspServlet.java:292)
at org.apache.jasper.servlet.JspServlet.service(JspSe rvlet.java:236)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:802)
at org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter
(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.do Filter
(ApplicationFilterChain.java:157)
at glucoweb.LoginFilter.doFilter(LoginFilter.java:106 )
at org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter
(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.do Filter
(ApplicationFilterChain.java:157)
at org.securityfilter.filter.SecurityFilter.doFilter
( SecurityFilter.java:188)
at org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter
(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.do Filter
(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invo ke
(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext
(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke
(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal
(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke
(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext
(StandardValveContext.java:104)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke
(AuthenticatorBase.java:540)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run
(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:595)

can you help me?

[Ed]

Can you paste the code?
maybe it's a syntax problem