PHP作为Javascript，GET参数

I have a file javascript.php which is inserted into my PHP File like this

$data = array(...Some parameters...);
echo '<script src="path/to/file/javascript.php?'.http_build_query($data).'" type="text/javascript"></script>'."
";

The javascript.php file looks like this:

<?php header('Content-Type: text/javascript'); ?>

$(window).load(function() {
    alert('Loaded: <? $_GET['someparameter'] ?>');
});

But it only alerts Loaded: nothing with the $_GET.

What did I do wrong, how can I get the Parameters of the URI?

instead using:

alert('Loaded: <? $_GET['someparameter'] ?>');

use like this:

alert('Loaded: <?php echo $_GET['someparameter'] ?>'); 

You've missed the =.

<?=$_GET['someparameter'] ?>