Why This Cannot Redeclare Function Error ?

This is just downright ridiculous!

Can someone tell me why I get this ridiculous error ?
**Fatal error: Cannot redeclare filter_input() in C:xampphtdocsTemplatestest.php on line 12**

Where on earth am I redeclaring the filter_input() ?
Check my code and notice the code comment.

[code]
<?php

$input = ‘<a href=”http://www.site.com/index~1.html”>http://www.site.com/index~1.html</a>’;

function filter_input($data)
{
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);

return $data;
} //LINE 12 is here. Where am I redeclaring filter_input() on this line ?

echo filter_input($input);

echo $input;
echo ‘<br>’;
echo $data;

die;

?>

[/code]

Stopped and restarted my local webserver. Shut down and re0opened FireFox. Same issue.

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