<?php
require("connect.php");

if($_POST['submit']){
    $create = mysql_query("INSERT INTO users (first_name) VALUES('{$_POST['username']}')") or die(mysql_error());
}

$extract = mysql_query("SELECT * FROM users");
while($row = mysql_fetch_array($extract)){
echo $row['first_name']."<br/";
}
?>