--- originale ----
<html>
<head>
<title></title>
<script type="text/javascript" src="giro.js"> </script>
--- ----

1°prova -----
<?php
$pagina="giro.js";
?>

<html>
<head>
<title></title>
<script type="text/javascript" src="<?php echo'$pagina'; ?>"> </script>

2°prova ---- passato valore con GET
<?php
$pagina=$_GET['NomePagina'];
?>

<html>
<head>
<title></title>
<script type="text/javascript" src="<?php echo'$pagina'; ?>"> </script>