hai provato con urlencode() und urldecode() ?

Codice PHP:
<?php

$sql
="select * from LUOGHI";
$result=mysql_query($sql);
$nrighe=mysql_num_rows($result);
$i=0;

print 
"<table border=2 align=center>";
print 
"<tr><th>Nome Cantiere</th><th>Provincia</th><th>Citta</th><th>Via</th><th>Numero</th><th>Operazione</th></tr>";

while(
$i<$nrighe){
    
$nomeCant=mysql_result($result,$i,0);
    
$provincia=mysql_result($result,$i,1);
    
$citta=mysql_result($result,$i,2);
    
$via=mysql_result($result,$i,3);    
    
$numero=mysql_result($result,$i,4);
    print 
'
        <tr><td>$nomeCant</td><td>$provincia</td><td>$citta</td><td>$via</td><td>$numero</td><td>
            <form action="OpenMaps.php" method="POST">
                <input type="hidden" name="luogo" value="<?php urlencode($nomeCant) ?>" />
                <input type="submit" value="Visualizza" />
            </form>
        </td><tr>'
;
    
$i=$i+1;
}

print 
"</table> </br> ";

?>