I used both IE and Mozilla Firefox but problem persisted.

I doubt it is due to browser because when i hosted on localhost 127.0.0.1,it was working perfectly fine. but as i changed it to ip address of machine on lan ,it doesn't load(Only pop up window opens up and shows chat loading) . Other features of site load well.

Sounds like you have having a cache problem. You will need to rehash to reset your settings or manually clear your chat cache. If the chat won't load, your only option is to do it manually.

If I remember correctly, there is a folder in the chat plugin called pfc. In that folder is a folder called data. The data folder has two folders in it private and public. Delete everything in the private folder except .htaccess. Close your chat window (either popup or embedded view) and try it again. It should load. This is a common problem with pfc. Their website has good information on trouble shooting.

php free chat

Thanks Brian for your advice..

I deleted everything in the private folder except .htaccess and it worked :)