<?php
    $first_name = '';
    $last_name = '';
    $city = '';
    $error = false;
     if(isset($_POST['first_name'])) {
        $first_name = $_POST['first_name'];
    }
     if(isset($_POST['last_name'])) {
        $last_name = $_POST['last_name'];
    }
     if(isset($_POST['city'])) {
        $city = $_POST['city'];
    }
?>
<style>
    h2 {
        font-size: 15px;
        color: green;
    }
    .error {
        background-color: red;
        padding: 10px;
        font-size: 20px;
        color: white;
    }
    .fields {
        padding: 10px;
    }
    .button{
        padding: 10px;
        margin: 10px;
        font-size: 20px;
        border-radius: 10px;
    }
</style>

<h1>My Final Project</h1>
<hr />

<form method="POST">
    <div class="fields">
        <label for="first_name">First Name *</label>
        <input type="text" value="<?php echo $first_name; ?>"
            name="first_name"
            required="required">
        <?php
        if(isset($_POST['first_name']) &&
            empty($_POST['first_name'])) {
            echo "<div class='error'>
                    *You must fill in all fields*
                    </div>";
        }?>
    </div>
    <div class="fields">
        <label for="last_name">Last Name *</label>
        <input type="text" value="<?php echo $last_name; ?>"
            name="last_name"
            required="required">
        <?php
         if(isset($_POST['last_name']) &&
            empty($_POST['last_name'])) {
            echo "<div class='error'>
                    *You must fill in all fields*
                    </div>";
        }
         ?>
    </div>
    <div class="fields">
        <label for="city">City *</label>
        <input type="text" value="<?php echo $city; ?>"
            name="city"
            required="required">
        <?php
            if(isset($_POST['city']) &&
            empty($_POST['city'])) {
            echo "<div class='error'>
                    *You must fill in all fields*
                    </div>";
        }
         ?>
    </div>
     <button class="button" type="submit">Submit</button>
</form>



       <?php
        if($error = true) {

        } else {
            echo "<h2>Form Submitted Successfully</h2>";
        }

        print_r($_POST);

     ?>