php page being downloaded instead of being processed while accessing outside a particular domain

I have installed PHP5 with apache 2.2.16 and trying to serve an application based on php.

I am able to acess this application inside a particular domain (php scripts are processed normally) but when i trying to access it outside t开发者_C百科hat domain my php pages are being downloaded instead of being processed ?

What could be the reason?

Are you sure Apache and PHP5 are properly installed? If Apache is not actually parsing the php files after you've installed PHP5 and restarted the server, install libapache2-mod-php5. This is usually installed when you initially install the PHP5 package, but perhaps it might have been moved or removed intentionally or inadvertently by other packages which need other PHP versions.

You may also need to actually enable PHP by doing sudo a2enmod php5 followed by sudo /etc/init.d/apache2 restart. If sudo a2enmod php5 returns "$ This module does not exist!", you should purge (not just remove) the libapache2-mod-php5 package and reinstall it.