I finally used the root user
1.C:\Sun\AppServer\mysql\bin>mysqladmin -u root password root.
I referred
this link for setting the password
2.C:\Sun\AppServer\mysql\bin>mysql -u root -p
Enter password: **** <- enter
root here
Onnce I was able to pin down the user name and password, I changed the persistence.xml and successfully executed the application.
Thanks a lot for the help!