Erro aplicação java web

Pessoal, estou tendo problemas ao executar pela IDE eclipse um servlet…ja adicionei no classpath a servelet-api.jar… mas agora estou tendo este erro:
veja:

SEVERE: Error loading WebappClassLoader

delegate: false

repositories:

/WEB-INF/classes/

----------> Parent Classloader:

org.apache.catalina.loader.StandardClassLoader@1549f94

java.AdicionaContato

java.lang.ClassNotFoundException: java.AdicionaContato

at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1360)

at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1206)

at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1083)

at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:806)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)

at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)

at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)

at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)

at java.lang.Thread.run(Unknown Source)

30/01/2009 00:53:04 org.apache.catalina.core.StandardWrapperValve invoke

SEVERE: Allocate exception for servlet testaServlet