Apache Set Expires Header for Images/CSS

<IfModule mod_expires.c>
ExpiresActive on
ExpiresDefault "access plus 30 seconds"
ExpiresByType text/html "access plus 15 days"
ExpiresByType image/gif "access plus 1 months"
ExpiresByType image/jpg "access plus 1 months"
ExpiresByType image/jpeg "access plus 1 months"
ExpiresByType image/png "access plus 1 months"
ExpiresByType text/js "access plus 1 months"
ExpiresByType text/javascript "access plus 1 months"
</IfModule>