Wrong jar files?

[Bobert]

Hi,

I get the following error
Description Resource Path Location Type
The project was not built since its build path is incomplete. Cannot
find the class file for org.eclipse.jetty.util.Attributes. Fix the
build path then try building this project Subscriber-v0.3

Description Resource Path Location Type
The type org.eclipse.jetty.util.Attributes cannot be resolved. It is
indirectly referenced from required .class files Web.java /Subscriber-
v0.3/src/PubSubHubbub line 65

I use
jetty-server-7.0.1.v20091125.jar
servlet-2.3.jar
httpclient-4.1.jar
httpcore-4.1.jar
rome.jar

What am I doing wrong

Thanx Bobert