jstl error

[calvi]

In my .jsp page i include the taglib:
<%@taglib prefix="c" uri="

http://java.sun.com/jsp/jstl/core"

%> in order that I can use the <c:forEach> but I got an error:
The absolute uri

http://java.sun.com/jsp/jstl/core

cannot be resolved in either web.xml or the jar files deployed with this application.
I use the java tools bundle window with netbeans included.