Help: Inserting javascript in posts(jquery truncate) not working!

Hi, I want to truncate the words with jquery javacript like +more and -less and I have added the code in sigle.php file(only posts).
I have downloaded the plugin from here:
http://plugins.learningjquery.com/expander/index.html#getting-started
I tested many things,adding plugins wordpress like javascript logic to be allowed to insert javascript in wordpress.. but still not working.
Can someone help please?
I’m testnig my site in local server and is not yet online.
Thanks,
Best regards