<IfModule mod_rewrite.c>
RewriteEngine On

#Checks to see if the user is attempting to access a valid file,
#such as an image or css document, if this isn't true it sends the
#request to index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
#This last condition enables access to the images and css folders, and the robots.txt file
RewriteCond $1 !^(index\.php|application\/modules|public|robots\.txt)
RewriteRule ^(.*)$ index.php?/$1 [L]
</IfModule>