验证电子邮件PHP

Question

I am trying to add onto my current PHP script (below) to now validate if a user put in a correct Email. My PHP below is to send a form to an Email address, and now I added onto it to validate the Email. What am I doing wrong? I am getting the $output_form = true/false; from the book Head First PHP & MySQL. The book does not teach me how to add onto my original PHP script to send an Email.

<?php
$myname = $_POST['name'];
$myemail = $_POST['email'];
$mytelephone = $_POST['telephone'];
$what_service = $_POST['service'];
$mycomments = $_POST['comments'];

if (isset($POST['submit'])) {
$to = '[e-mail]';
$subject = 'Contact Us - My Business';
$msg = "Name: $myname
" .
"Service: $what_service
" .
"Telephone #: $mytelephone
" .
"Comments: $mycomments";
mail ($to, $subject, $msg, 'From:' . $myemail);
$output_form = false;

echo '<p>Thank you for contacting us!</p>';
echo 'Your Name: ' . $myname . '<br>';
echo 'Your E-Mail: ' . $myemail . '<br>';
echo 'Your Telephone: ' . $mytelephone . '<br>';
echo 'Your Service: ' . $what_service . '<br>';
echo 'Your Comments: ' . $mycomments;

if (!filter_var($myemail, FILTER_VALIDATE_EMAIL)) {
echo ' Invalid Email, please resubmit form.<br>';           
$output_form = true; } }
?>

Answer 1

I just rearranged your code to validate email first and mail on valid email:

<?php
$myname = $_POST['name'];
$myemail = $_POST['email'];
$mytelephone = $_POST['telephone'];
$what_service = $_POST['service'];
$mycomments = $_POST['comments'];

if (isset($POST['submit'])) {
    $to = '[e-mail]';
    $subject = 'Contact Us - My Business';
    $msg = "Name: $myname
" .
    "Service: $what_service
" .
    "Telephone #: $mytelephone
" .
    "Comments: $mycomments";
    if (!filter_var($myemail, FILTER_VALIDATE_EMAIL)) {
        echo ' Invalid Email, please resubmit form.<br>';           
        $output_form = true; 
    } else {
        if (mail ($to, $subject, $msg, 'From:' . $myemail)) {
            echo '<p>Thank you for contacting us!</p>';
            echo 'Your Name: ' . $myname . '<br>';
            echo 'Your E-Mail: ' . $myemail . '<br>';
            echo 'Your Telephone: ' . $mytelephone . '<br>';
            echo 'Your Service: ' . $what_service . '<br>';
            echo 'Your Comments: ' . $mycomments;
        } else {
            eccho 'Failed';
        }           
    }
}
?>