join2.php

<?php
$email = "";
$username = "";
$password = "";
if( isset($_POST['email']) ) {
    $email = $_POST['email'];
}
if( isset($_POST['username']) ) {
    $username = $_POST['username'];
}
if( isset($_POST['password']) ) {
    $password = $_POST['password'];
}
$joinok = 0;
if( $email && $username && $password ) {
    require("dbcon.php");
    $presql = "select email from user ";
    $presql .= " where email='{$email}'";
    $prers = $db->query($presql);
    $count = $prers->rowCount();
    if( $count == 0 )   {
        $sql = "insert into user set ";
        $sql .= " email='{$email}'";
        $sql .= ", username='{$username}'";
        $sql .= ", password='" . md5($password) . "'";
        $sql .= ", rdate=now()";
        if( $db->query($sql) ) $joinok = 1;
    }
}
echo $joinok;