将表单数据发送到codeIgniter中的管理员电子邮件

I am newer for codeigniter. I have an one contact form with fields of stream, name, email, contact. But I have an problem with form data are not send to admin email. When i tried to submit the data on contact form page source will alert but i have given other alert data. I have tried following code,I am newer for codeigniter. I have an one conta