Securing a contact form script

Question

Hello! I am just wondering how secure is this contactform script I just made? My teacher was nagging at me a long time ago when I made my contactforms.

Answer 1

You can use a function to validate the entries such as :

function check_input($data)
 {
    $data = trim($data);
    $data = stripslashes($data);
    $data = htmlspecialchars($data);
    return $data;
 }

And

   

        $name      =    check_input($_POST['name']);
        $email    =    check_input($_POST['email']);
        $phone    =    check_input($_POST['phone']);
        $subject  =    check_input($_POST['subject']);
        $comments =    check_input($_POST['comments']);

And

     if ($name && $email && $phone && $subject && $comments) {
         Send contact form...

}

and of course you can add captcha to make it more secure.