[Q] Need help on Servlet

Hi,
   I have spend 4 days on installing and running servlet with
jigsaw2.0beta1. And now, it seems that I have installed servlet on
jigsaw2.0b1. When I test the servlet, some error message appears:

1.    If I use JDK1.5 with jsdk2.0,  sometimes the error is  "Servlet
not configured properly", sometimes it says   "Document contains no
data" with lots of error in the backgroud:

 java.lang.IllegalAccessError: Unimplemented interface method
 at
 at
org.w3c.jigsaw.servlet.ServletWrapperFrame.perform(ServletWrapperFrame.java)

 at
org.w3c.tools.resources.FramedResource.performFrames(FramedResource.java)

 at org.w3c.tools.resources.FramedResource.perform(FramedResource.java)
 at org.w3c.jigsaw.http.httpd.perform(httpd.java)
 at org.w3c.jigsaw.http.Client.processRequest(Client.java)
 at org.w3c.jigsaw.http.Client.startConnection(Client.java)
 at org.w3c.jigsaw.http.socket.SocketClient.run(SocketClient.java)
 at org.w3c.util.CachedThread.run(ThreadCache.java)
java.lang.NoClassDefFoundError:
org/w3c/jigsaw/servlet/JigsawHttpServletRequest
 at
 at
org.w3c.jigsaw.servlet.ServletWrapperFrame.perform(ServletWrapperFrame.java)

 at
org.w3c.tools.resources.FramedResource.performFrames(FramedResource.java)

 at org.w3c.tools.resources.FramedResource.perform(FramedResource.java)
 at org.w3c.jigsaw.http.httpd.perform(httpd.java)
 at org.w3c.jigsaw.http.Client.processRequest(Client.java)
 at org.w3c.jigsaw.http.Client.startConnection(Client.java)
 at org.w3c.jigsaw.http.socket.SocketClient.run(SocketClient.java)
 at org.w3c.util.CachedThread.run(ThreadCache.java)

2.  If I use JDK1.2beta3 , the error is same with the second error
above.

3.  Could any tell me what is correct version of the jdk and jsdk can
run jigsaw2.0beat1?

Could any one help me?  I need to use servlets.  If possible, could
anyone tell me if there is another free web server support servlets?

Thank you.
------------
Lu Shan