<?php
include('_system/config.php');
{
    $mail = mysql_real_escape_string(strip_tags($_GET['mail']));
    $letscheck = mysql_query("SELECT * FROM `users` WHERE `mail` = '".$mail." LIMIT 1');
    if(mysql_num_rows($letscheck) = 0){
    echo "1";
    }else{
    echo "0";
}
?>