Spring AOP-DTD help

hi,
I was working on the AOP concepts and came across a code available in this site. The XML configuration in the sample code is given as http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
">
Additionally i used . But I am getting an error while trying to start the server. The error is given below.

Caused by: org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 3 in XML document from ServletContext resource [/WEB-INF/config/spring/context/context.xml] is invalid; nested exception is org.xml.sax.SAXParseException: Attribute "xmlns" must be declared for element type "beans".
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:404)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:342)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:310)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.importBeanDefinitionResource(DefaultBeanDefinitionDocumentReader.java:190)
... 34 more

Is it tat, DTD doesn;t support xmlns tag? I am using spring version 2.5.4 Can any one provide me with some pointer.