HTTP Status 403 -- Access to the requested resource has been denied

When I typed:
http://localhost:8080/manager/html, it prompts me to enter user name and password, then I got the above message. When I checked /tomcat/conf/tomcat-users.xml, both user name and password are matched as I typed. How to solve this error?

Thanks in advance.

please chk the URL, its must be in valid format

http://studyjava.org/forums/