$output .='<input type="hidden" id="cmd" name="cmd" value="_donations">
            <p class="donate_amount"><label for="amount">'.__('Importo', 'dplus').':</label><input type="text" name="amount" id="amount" value="'.$dplus['default_value'].'" /> <small>('.__('','dplus').$cur.')</small></p><span id="errd"></span>';

            <script type='text/javascript'>
            jQuery('#donateplusform').submit(function() {
            if (jQuery('#amount').val() >= ".$dplus['default_value'].")
            {
            return true;
            }
            else {
            jQuery('#errd').css('color', 'red');
            jQuery('#errd').text('Importo minimo: ".$dplus['default_value']." Euro').show();
            return false;
            });
            </script>