You can create a file named download.php with these contents:
PHP Code:
<?php
$beta = TRUE;
if ($beta === TRUE) { header("Location: http://www.fish-byte.com/MA3Beta.zip"); }
if ($beta === FALSE) { header("Location: https://prolific.s3.amazonaws.com/MarineAquarium3/Windows/MarineAquarium3.exe"); }
exit;
?>
Set $beta = TRUE if you want people to download from Fish-Byte.com.
Set $beta = FALSE if you want people to download it from SereneScreen.
Then no matter what, if they visit
http://www.fish-byte.com/download.php, they'll get redirected to download the correct file.