$Name = mysqli_real_escape_string($conn, $_POST['Name']);
 $Pass = mysqli_real_escape_string($conn, $_POST['Pass']);
 $PassMD5 = md5($Pass);

 $result1 = "SELECT * FROM users WHERE username = '$Name' && userpass = '$PassMD5' LIMIT 1";
 $result2 = mysqli_query($conn, $result1);
 $result3 = mysqli_fetch_assoc($result2);

 if(isset($result3)){
    echo "SUCCESS";
 }else{
    echo "FAIL";
 }