PHP表单，如果没有正确填写，所有字段都清除自己

Question

I made a contact form following this tutorial : http://tinyurl.com/nyxv8ub

Everything is working but some parameters are not adressed.

As a matter of fact, on submit, if the user hasn't filled the form properly he is notified and all fields clear themselves.

It is a pain for the user to re-type his message, so I'd like him to be notified of his mistakes without clearing any field.

Currently, there are 2 ways to get the form wrong. Whether you don't fill the Email or Name fields, or when the answer to the spam question is wrong.

Is it possible to prevent this from happening?

You can find the form here : http://bettercheckthekids.com/Form/index.php

And here is the php :

<?php
    $name = $_POST['name'];
    $firm = $_POST['firm'];
    $email = $_POST['email'];
    $list = $_POST['list'];
    $message = $_POST['message'];
    $spam = $_POST['spam'];
    $from = 'From: Adiwatt Online'; 
    $to = '[e-mail]'; 
    $subject = 'Hello';

    $body = "From: $name
 Firm: $firm
 E-Mail: $email
 Objet: $list
 Message:
 $message";
    ?>


    <?php
    if ($_POST['submit']) {
    if ($name != '' && $email != '') {
        if ($spam == '4') {                 
            if (mail ($to, $subject, $body, $from)) { 
            echo '<p>Your message has been sent!</p>';
        } else { 
            echo '<p>Something went wrong, go back and try again!</p>'; 
        } 
    } else if ($_POST['submit'] && $spam != '4') {
        echo '<p>You answered the anti-spam question incorrectly!</p>';
    }
    } else {
        echo '<p>You need to fill in all required fields!!</p>';
    }
    }
    ?>

Answer 1

First of all, I would separate the backend code from the structure as much as possible. I would not generate the html inside the php code if I had any other option. Your structure should look like this:

<form method="post" action="index.php"> 
    <label>Name *</label>
    <input name="name" placeholder="..." value="<?php echo ((isset($_POST["name"])) ? (htmlspecialchars($_POST["name"], ENT_QUOTES)) : ("")); ?>">

    <label>Firm</label>
    <input name="firm" placeholder="..." value="<?php echo ((isset($_POST["firm"])) ? (htmlspecialchars($_POST["firm"], ENT_QUOTES)) : ("")); ?>">

    <label>Email *</label>
    <input name="email" type="email" placeholder="..." value="<?php echo ((isset($_POST["email"])) ? (htmlspecialchars($_POST["email"], ENT_QUOTES)) : ("")); ?>">

    <label>Object</label>
    <select name="list" id="list"> 
       <option value="Pas d'objet" <?php if ((isset($_POST["list"])) && ($_POST["list"] === "Pas d'objet")) {echo "selected";} ?>>--</option> 
       <option value="Je veux sortir" <?php if ((isset($_POST["list"])) && ($_POST["list"] === "Je veux sortir")) {echo "selected";} ?>>Object 1</option> 
       <option value="Je sortirai demain" <?php if ((isset($_POST["list"])) && ($_POST["list"] === "Je sortirai demain")) {echo "selected";} ?>>Object 2</option> 
       <option value="Je n'ai pas d'argent" <?php if ((isset($_POST["list"])) && ($_POST["list"] === "Je n'ai pas d'argent")) {echo "selected";} ?>>Object 3</option> 
    </select> 

    <label>Message</label>
    <textarea name="message" placeholder="..."><?php echo ((isset($_POST["message"])) ? (htmlspecialchars($_POST["message"], ENT_QUOTES)) : ("")); ?></textarea>

    <label>What is 2+2? (Anti-spam) *</label>
    <input name="spam" placeholder="..." value="<?php echo ((isset($_POST["spam"])) ? (htmlspecialchars($_POST["spam"], ENT_QUOTES)) : ("")); ?>">    

    <input id="submit" name="submit" type="submit" value="Send">
</form>

Cheers!