I've been using Tomcat for some time however, i only started to explore the in-built Manager.

Hi all, i've solved the problem. To those who had the similiar problem, your tomcat-users.xml should include one more role, 'admin'..e.g.

<?xml version='1.0' encoding='utf-8'?>
<tomcat-users>
<role rolename="admin"/>
<role rolename="manager"/>
<role rolename="tomcat"/>
<role rolename="role1"/>
<user username="admin" password="secret" roles="manager,admin"/>
<user username="tomcat" password="tomcat" roles="tomcat"/>
<user username="role1" password="tomcat" roles="role1"/>
<user username="both" password="tomcat" roles="tomcat,role1"/>
</tomcat-users>

Hope it will help those who had the similiar problem :)
Joe