Validation with variables

This way doesn't work. Data is neve valid. Always that is NOT valid.

$this->form_validation->set_rules($email , 'Users email', 'required|valid_email');

if ($this->form_validation->run() == FALSE)
{
echo " Submitted data IS NOT valid";
}
else
{
echo " Submitted data IS valid";
}

$email is the variable where I put the valid email to test. Am I doing something wrong?