don't send the form message if input is empty - php

Question

i do have a little problem with my contact.php :(
I needed for my page a contact form (very simple, just name, email and message).
It works perfectly but it sends the message even if the inputs are empty. My inputs do have "required" but it doesn't seem to work. My php skills are not that great. But you understand for sure where the problem is.
If there are empty fields, the form should not send the message and show an alert.
My current code:
HTML
<form method="post" id="myform" action="contact.php">
<div class="field half first">
<label for="name">Ihr Name</label>
<input type="text" name="name" id="name" required="required">
</div>
<div class="field half">
<label for="email">Ihre E-Mail</label>
<input type="text" name="email" id="email" required="required">
</div>
<div class="field">
<label for="message">Ihre Nachricht</label>
<textarea name="message" id="message" rows="5" required="required"></textarea>
</div>
<ul class="actions">
<li>
Senden
</li>
</ul>
</form>
contact.php
<?php
$field_name = $_POST['name'];
$field_email = $_POST['email'];
$field_message = $_POST['message'];
$mail_to = 'mail#gmail.com';
$subject = 'Nachricht von '.$field_name;
$body_message = 'Von: '.$field_name."\n";
$body_message .= 'E-mail: '.$field_email."\n";
$body_message .= 'Nachricht: '.$field_message;
$headers = 'Von: '.$field_email."\r\n";
$headers .= 'Antworte an: '.$field_email."\r\n";
$mail_status = mail($mail_to, $subject, $body_message, $headers);
if ($mail_status) { ?>
<script language="javascript" type="text/javascript">
alert('Ich bedanke mich für Ihre Nachricht. Bald werde ich Sie kontaktieren./ Thank you for your message.');
window.location = 'http://';
</script>
<?php
}
else { ?>
<script language="javascript" type="text/javascript">
alert('Senden fehlgeschlagen./ Could not send the message');
window.location = 'http://';
</script>
<?php
}
?>
Any ideas, how to fix that small problem? :(

Answer 1

I think if your goal is to prevent someone send a blank message/contact, just use "required" in the end of your input tag like this :
<input type="text" name="something" required/>
or in your case, it should be like this :
<form method="post" id="myform" action="contact.php">
<div class="field half first">
<label for="name">Ihr Name</label>
<input type="text" name="name" id="name" required>
</div>
<div class="field half">
<label for="email">Ihre E-Mail</label>
<input type="text" name="email" id="email" required>
</div>
<div class="field">
<label for="message">Ihre Nachricht</label>
<textarea name="message" id="message" rows="5" required></textarea>
</div>
<ul class="actions">
<li>
Senden
</li>
</ul>
</form>
The "required" is a simple html5 tag attribute that helps you prevent someone send a blank form. I hope it works on you, make sure you are working with html5.

Answer 2

There is a function in PHP called empty(). You can combine this with the $_POST function like this example:
<?php
// The form is submitted.
if(isset($_POST["submit_button"])) {
// Now check if the posted input element is empty, if empty stop by echo a error message
// Otherwhise continue executing script
if(empty($_POST["form_name"])) {
echo "You forgot to fill in this form-element.";
}else{
// Continue
}
}
?>
Read more about this function: http://php.net/manual/en/function.empty.php

Answer 3

Check if the form is submitted using isset() function:
isset — Determine if a variable is set and is not NULL
Then, check if the fields are filled using empty() function:
empty — Determine whether a variable is empty
// this will return true if the Submit Button is clicked
if(isset($_POST["submit_button"])) {
if(empty($_POST['name']) {
echo "Name is not filled";
} else if (empty($_POST['email']) {
echo "Email is not filled";
} else if (empty($_POST['message']) {
echo "Message is not filled";
} else {
// Your original code
}