I'm facing an issue with Apache proxy module.ProxyPass isn't working.Why is that?Please help me.

.ProxyPass isn't working.Why is that?

It's not configured/installed right. That's the best answer anyone can give with the information you've given.

Sorry....i forgot to mention that.No i have installed/configured that.And my development environment is Ubuntu and Apache 2.

First, you aren't providing enough information. Second what did you do to install/configure it? Finally, please post configuration information here for us to look at. Just stating "I have a problem" isn't too useful...

Ok.Sorry for that.Actually i enabled apache proxy module.After that i put this code inside default apache configuration file before between <VirtualHost> tags

<VirtualHost *:80>
ProxyRequests On
ProxyVia On
<Proxy *>
      Order deny,allow
      Deny from all
      Allow from localhost
ProxyPass /app_item/ http://localhost/app/item
ProxyPassReverse /app_item/ http://localhost/app/item