Your issue is not related to Oracle PL/SQL, you can ask it in Apex Oracle Application Express (APEX) forum.
Check this thread and links may help you.
Hope it helps you.
*** Moderator action - Question now moved from PL/SQL and SQL to Application Express space ***
Thanks for the reply,
By Mistake, I have put this question in sql, plsql forum.
I have read the links which you have sent to me. But, following those links, din't work for me.