Read the JDBC tutorials at Sun, the JDBC documentation for the PostGreSQL Driver (once you download it), and the J2EE tutorial at Sun.

I have postgresql in my system.also i created schema and table there. i need the coding for connecting that database and my JSP program.

And I pointed you to resources that will enable you to do that. The first one will teach you how to use JDBC. The second one will provide you the specifics (read Connection URL) for PostGreSQL, the third one will help you integrate that information into JSP (and hopefully you will do it in the proper manner and use a bean or JSTL tag for accessing the DB rather than a scriptlet).

Here are the three resources as links:

http://java.sun.com/docs/books/tutorial/jdbc/index.html
http://jdbc.postgresql.org/doc.html
http://java.sun.com/j2ee/1.4/docs/tutorial/doc/

I am not going to simply give you ready made code. Try it yourself, and if you have problems post your code here and we will help to correct it.

and learn proper separation of control. JSP are not meant for that.