<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteBase /projectName/
    RewriteCond %{REQUEST_URI} ^system.*
    RewriteRule ^(.*)$ /index.php?/$1 [L]
    RewriteCond %{REQUEST_URI} ^application.*
    RewriteRule ^(.*)$ /index.php?/$1 [L]
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^(.*)$ index.php?/$1 [L]
</IfModule>
 # If we don't have mod_rewrite installed, all 404's
  # can be sent to index.php, and everything works as normal.
  # Submitted by: Pawan Nagar
<IfModule !mod_rewrite.c>
   ErrorDocument 404 /index.php
</IfModule> 