spring xml tag constraint error

Multiple annotations found at this line:
    - cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'context:component-scan'.
    - schema_reference.4: Failed to read schema document 'http://www.springframework.org/schema/context/spring-context.xsd', because 1) could not find the document; 
     2) the document could not be read; 3) the root element of the document is not <xsd:schema>.

Add this line

xmlns:dwr="http://directwebremoting.org/schema/spring-dwr/spring-dwr-3.0.xsd"