echo an error message for each input in form - php

Question

i have a form with input for name and e-mail. I would like to have a dedicated error-message for each input - fx
if no name is written it will say "please write your name!"
and if the e-mail is missing or not valid it echoes "wrong mail - try again!"
At the moment I have only 1 error-message that will echo for both situations.
How can i assign an dedicated error-message for each of the inputs?
Heres the code:
<?php
//If the form is submitted
if(isset($_POST['submit'])) {
//Check to make sure that the name field is not empty
if(trim($_POST['contactname']) == '') {
$hasError = true;
} else {
$name = trim($_POST['contactname']);
}
//Check to make sure sure that a valid email address is submitted
if(trim($_POST['email']) == '') {
$hasError = true;
} else if (!eregi("^[A-Z0-9._%-]+#[A-Z0-9._%-]+\.[A-Z]{2,4}$", trim($_POST['email']))) {
$hasError = true;
} else {
$email = trim($_POST['email']);
}
//If there is no error, send the email
if(!isset($hasError)) {
$emailTo = '##gmail.com'; //Put your own email address here
$body = "Name: $name \n\nEmail: $email \n\nComments:\n $comments";
$headers = 'From: My Site <'.$emailTo.'>' . "\r\n" . 'Reply-To: ' . $email;
mail($emailTo, $subject, $body, $headers);
$emailSent = true;
}
}
?>
<article class="kontakt">
<?php if($_POST['contactname'] != '') { //echo when a name was entered ?>
<!--<p> Hello </p>-->
<?php $name = strip_tags(trim($_POST['contactname']));
echo $name;
} ?>
</article>
<article class="kontakt">
<?php if(isset($hasError)) { // THIS PART IS ECHOED IN BOTH SITUATIONS - should only apply for error in e-mail?>
<p class="error"> Your mail is <span style="color: orange"> not correct</span> - try again! </p>
<?php } ?>
<?php if($_POST['email'] != '') { // echo when a valid mail was entered ?>
<p> Hello </p>
<?php $name = strip_tags(trim($_POST['email']));
echo $email;
} ?>
</article>
<article class="kontakt">
<?php if(isset($emailSent) && $emailSent == true) { //If email is sent ?>
<p> Your message is sent !</p>
<?php } ?>
</article>
}
?>

Answer 1

try something like:
if(trim($_POST['contactname']) == '') {
$hasError['contactname'] = 'Please enter a contact name!';
} else {
$name = trim($_POST['contactname']);
}
//Check to make sure sure that a valid email address is submitted
if(trim($_POST['email']) == '') {
$hasError['email'] = 'Please enter email!';
} else if (!eregi("^[A-Z0-9._%-]+#[A-Z0-9._%-]+\.[A-Z]{2,4}$", trim($_POST['email']))) {
$hasError['validemail'] = 'Please enter valid email';
} else {
$email = trim($_POST['email']);
}
and this to display errors:
if(isset($hasError)){
echo '<ul>';
foreach($hasError as $error){
echo '<li>'.$error.'</li>';
}
echo '</ul>';
}
and this to keep old values upon error
<div class="right_wrap">
<div class="header"> <h5><span style="color: white"> mail </span></h5> </div>
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>" id="contactform">
<article class="kontakt">
<label for="name"> Dit navn </label>
<input type="text" name="contactname" id="contactname" value="<?php echo $_POST['contactname']; ?>" class="" />
</article>
<article class="kontakt">
<label for="email"> Din mail </label>
<input type="text" name="email" id="email" value="<?php echo $_POST['email']; ?>" class="required email" />
</article>
<article class="kontakt" style="height: auto">
<label for="message"> Din besked </label>
<textarea rows="5" cols="50" name="message" class="required"><?php echo $_POST['message']; ?></textarea>
</article>
<article class="kontakt">
<input type="submit" value="Send besked" name="submit" class="button"/>
</article>
</form>
</div> <!--end of right_wrap -->

Answer 2

You treat each input with individual code that means you don't have much data-structure here.
Normally some kind of model for inputs as well as associated errors and values is helpful to get things done with forms.
A lightweight entry that normally works pretty well with individual PHP scripts is HTML_QuickForm2.
It does take care of individual error messages as well. You naturally can write that your own and luckily it is free software so you are allowed to study the code and learn from it.

Answer 3

Heres the actual form - some danish words in it. Whatever errors / messages will be output in a left wrap div - so cant be placed inside the actual form.
<div class="right_wrap">
<div class="header"> <h5><span style="color: white"> mail </span></h5> </div>
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>" id="contactform">
<article class="kontakt">
<label for="name"> Dit navn </label>
<input type="text" name="contactname" id="contactname" value="" class="" />
</article>
<article class="kontakt">
<label for="email"> Din mail </label>
<input type="text" name="email" id="email" value="" class="required email" />
</article>
<article class="kontakt" style="height: auto">
<label for="message"> Din besked </label>
<textarea rows="5" cols="50" name="message" class="required"></textarea>
</article>
<article class="kontakt">
<input type="submit" value="Send besked" name="submit" class="button"/>
</article>
</form>
</div> <!--end of right_wrap -->