I used this function to start a form:
echo form_open('email/send');
and after viewing the source I found that form_open returned duplicated index.php :
<form action="http://localhost/ci/index.php/index.php/email/send"
Note:
I tried keeping only this line of code in the page, but still gave me the same result
Edit1:
Base url : $config['base_url'] = 'http://localhost/ci/index.php/';