Hi!
I’ve tried also with:
<?php
$field_key = "field_5265167430efd";
$value = htmlentities($_GET['compilatore']);
update_field( $field_key, $value )?>
<div class="row-fluid">
<input type="text" id="ai1ec_compilatore" name="compilatore"
class="span12" />
</div>
but it doesn’t work 🙁