<?php
define("SQL_HOST", "localhost");
define("SQL_DATABASE", "test");
define("SQL_USERNAME", "root");
define("SQL_PASSWORD", "");
//Change the above variables to your own
define("MYPASSWORDSHA1", "my sha1 password salt");
//Current password is sha1('password') so you should go to an online SHA1 generator and
//generate a better password for your admin page.

if(!isset($_POST['password'])) //If they have not entered a password
{
    echo "<h1>Administration</h1><br />
    <form action='admin.php' method='post'>
    Password: <input name='password' type='password' maxlength='500'><br />
    <input name='submit' type='submit'>
    </form>";
}
if(isset($_POST['password'])) //If they have entered a password
{
    $password = sha1($_POST['password']); //Make input SAH1
    if($password != MYPASSWORDSHA1) die("Incorrect Password"); //Compare
    else
    {
        $con = mysql_connect(SQL_HOST, SQL_USERNAME, SQL_PASSWORD); //Connect to the SQL server
        mysql_select_db(SQL_DATABASE, $con); //Connect to the SQL DB
        $result = mysql_query("SELECT * FROM info"); //Select the whole table
        echo "<h1>Information de la base de donnée</h1><br /><table width='900'><tr><td>Prenom</td><td>Email</td><td>Reponse</td></tr>"; //Create the first line telling us what easy collumn is
        while($values = mysql_fetch_assoc($result))
        {
            echo "<tr><td>" . $values['nom'] . "</td><td>" . $values['email'] . "</td><td>" . $values['reponse'] . "</td></tr>"; //We echo the whole SQL table into a table :)
        }
        echo "</table>";
        mysql_close($con);
    }
}
?>


and my index.php

    <?php
define("SQL_HOST", "localhost");
define("SQL_DATABASE", "test");
define("SQL_USERNAME", "root");
define("SQL_PASSWORD", "");

//Above you change localhost, testx, root, etc to your own database information

if(!isset($_POST['nom']) && !isset($_POST['email']) && !isset($_POST['box'])) //If the info hasn't been submitted
{
    //Apply the information inserting page
    echo
    "
    <h1>Enter your info</h1><br />
    <form action='index.php' method='post'>
    Name: <input name='nom' type='text' size='30' maxlength='100' /><br />
    Email:  <input name='email' type='text' size='30' maxlength='200' /><br />
    Colour:
    <select name='reponse'>
        <option value='blue'>Blue</option>
        <option value='green'>Green</option>
        <option value='orange'>Orange</option>
        <option value='black'>Black</option>
    </select><br />
    <input name='submit' type='submit'>
    </form>
    ";
}
else if(isset($_POST['name']))
{
    //Sanitize our strings
    $name = htmlentities(mysql_escape_string($_POST['nom']));
    $email = htmlentities(mysql_escape_string($_POST['email']));
    if(!filter_var($email, FILTER_VALIDATE_EMAIL)) die("Invalid email"); //Check for a valid email
    $colour = htmlentities(mysql_escape_string($_POST['reponse']));
    $con = mysql_connect(SQL_HOST, SQL_USERNAME, SQL_PASSWORD); //Connect to the SQL server
    mysql_select_db(SQL_DATABASE, $con); //Connect to the DB
    $result = mysql_query("SELECT name FROM info WHERE email='$email' AND name='$nom'"); //Checks if there is someone with the same name and email already
    if(mysql_num_rows($result) != 0) echo("You have already submitted your name and email!");//Tells them they already have submitted
    else
    {
        mysql_query("INSERT INTO info (nom, email, reponse) VALUES ('$nom', '$email', '$reponse')"); //Insert into DB
        echo "Information submitted!";
    }
    mysql_close($con);
}
?>