I've been following a login system tutorial. You can find it [here](https://www.youtube.com/watch?v=HY08_fhcEC4). There are 2 parts of coding C# and PHP. The C# part is working fine but my PHP part returning error. Here is my PHP code:

```
<?php

    $servername = getenv('IP');
    $username = getenv('C9_USER');
    $passwordp = "";
    $database = "game_database";
    $dbport = 3306;

    // Create connection
    mysql_connect($servername, $username, $passwordp, $dbport)or die("Cant Connect to server");
    mysql_select_db($database) or die("Cant connect to database");
    // Check connection

$Email = $_REQUEST["Email"];
$Password= $_REQUEST["Password"];

if (!$Email || !$Password){
    echo"Email or password must be used";
}
else{
    $SQL = "SELECT * FROM 'users' WHERE Email = '"  . $Email ."'";
    $result_id = @mysql_query($SQL) or die("Database Error");
    $Total = mysql_num_rows($result_id);
    if ($Total){
        $datas = @mysql_fetch_array($result_id);
        if (strcmp($Password, $datas["Password"])){
                    $sql2 = "SELECT Characters FROM users WHERE Email = '" . $Email ."'";
                    $result_id2 = @mysql_query($sql2) or die("Database Error!!!");
                    while ($row = mysql_fetch_array($result_id2)){
                        echo $row ["Characters"];
                        echo ":";
                        echo "Success";
                    }
        }
        else{
            echo "WrongPassword";
        }
        }else {
            echo "NameDoesNotExist";
        }
    }

?>

```

It seems the error comes from $result\_id but I'm not sure?