OUI-10020: A write lock cannot be obtained.

Problem Description
While using OUI it fails with following message,
OUI-10020:The target area /oracle/10gR2/oraInventory is being used by another session. A write lock cannot be obtained.

Cause of The Problem
There is some process or software that holds lock on the /oracle/10gR2/oraInventory file. Until that software release lock OUI continues to display message OUI-10020.

Solution of The Problem
1.Go to the oraInventory directory.
$cd /oracle/10gR2/oraInventory

2. See the contents of it.
$ls /oracle/10gR2/oraInventory
You will see the locks directory here.

3.Go to the lock directory and delete the read lock under the directory.
$cd locks
$ rm /oracle/10gR2/oraInventory/locks/reader0.lock

4.Now run your Oracle Universal Installer.