The logics of this sample will guide you to solve your problem. Linking to your download page will involve the same programming logics as this sample. You may try something like:
<?php
if(isset($_REQUEST['sign'])){
if($_REQUEST['sign'] == 'signup'){
header("Location: /page0.php");
}
elseif($_REQUEST['sign'] == 'signin'){
header("Location: /page1.php");
}
}
?>;
Hope this works for you, and helps you solve your problem.
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