PHP check if user typed something in text input

Question

I have a few simple html text inputs. I would like to check that the user inputted something and not just spaces. My code below isn't working.

HTML (in a form):

<input type='text' name='email' id='email' />

PHP (the "action" page of the form):

$email=mysql_real_escape_string(strtolower(trim($_POST['email'])));

    if (!$email || empty($email)){    // these are the checks that don't work
           echo "no email entered";
     }

Answer 1

First, you should use mysql_real_escape_string only when inputting data inside of mysql. Don't use it while checking.

My typical manual verification syntax is this:

if(!isset($_REQUEST['email']) || strlen(trim($_REQUEST['email'])) == 0){
    $errors[] = 'No email provided';
}

Then after checking, use mysql_real_escape_string while inputting data into mysql

mysql_query('UPDATE myusers SET email = "'.mysql_real_escape_string($_REQUEST['email']).'" WHERE id = "'.mysql_real_escape_string($_REQUEST['id']).'"');

Good luck