Enabling iSQL*Plus DBA Access [ in Oracle 10.2.0 g ]

From past two days i'm trying to login  into iSQL*Plus DBA workspace but was not able to login though i was able to login into Enterprise manager. Each time i was getting "401 unauthorized access message ", and following errors:

ERROR - ORA-12154: TNS:could not resolve the connect identifier specified   

Solution: Enable iSQL*Plus DBA Access first

After googling too much i finally found the solution. To login into  iSQL*Plus DBA workspace first we have to Enable iSQL*Plus DBA Access. Following are the stages:

Create and Manage Users for the iSQL*Plus DBA URL

The actions available to manage users for the iSQL*Plus DBA URL are:

1. Create users
2. List users
3. Grant the webDba role
4. Remove users
5. Revoke the webDba role
6. Change user passwords

Starting the JAZN Shell

Open Command prompt and we perform these actions from the
"G:\oracle\product\10.2.0\db_1\oc4j\j2ee\isqlplus\application-deployments\isqlplus"
{Here installed directory is G drive in Window XP}
$JAVA_HOME is the location of your JDK (1.4 or above). It should be set to
$ORACLE_HOME/jdk, but you may use another JDK.
Note: change ORACLE_HOME variable according your environment.

To invoke JAZN Shell, use the following command all in the same line:

"g:\oracle\product\10.2.0\db_1\jdk\bin\java -Djava.security.properties=g:\oracle\product\10.2.0\db_1\sqlplus\admin\iplus\provider -jar g:\oracle\product\10.2.0
\db_1\oc4j\j2ee\home\jazn.jar -user "iSQL*Plus DBA/admin" -password welcome -shell" 

Default username : "iSQL*Plus DBA/admin" admin
Default password : welcome (small case) 
admin_password is the password for the iSQL*Plus DBA realm administrator user, admin. The password for the admin user is set to 'welcome' by default. You should change this password as soon as possible.

Creating Authorized user for "iSQL*Plus" DBA Access:

JAZN:> adduser "iSQL*Plus DBA" dba99 oracle

List Users:

JAZN:> listusers "iSQL*Plus DBA"
admin
dba99

Granting "webDba" roles to new users:

JAZN:> grantrole webDba "iSQL*Plus DBA" dba99
JAZN:> exit

Restart isqlplus services

You may need to restart iSQL*Plus for the changes to take effect.

G:\Oracle\product\10.1.0\Db_1\oc4j\j2ee\isqlplus\application-deployments\isqlplu
s>isqlplusctl stop
iSQL*Plus 10.1.0.5.0
Copyright (c) 2005 Oracle. All rights reserved.
Stopping iSQL*Plus ...
iSQL*Plus stopped.

G:\Oracle\product\10.1.0\Db_1\BIN>isqlplusctl start
iSQL*Plus 10.1.0.5.0
Copyright (c) 2005 Oracle. All rights reserved.
Starting iSQL*Plus ...
iSQL*Plus started.

Test iSQL*Plus DBA Access

Test iSQL*Plus DBA access by entering the iSQL*Plus DBA URL in your web browser:

http://machine_name.domain:5560/isqlplus/dba

A dialog is displayed requesting authentication for the iSQL*Plus DBA URL. Log in as the user you created above.