* @return <CODE>true</CODE> if the field was replaced, <CODE>false</CODE> if the field
     * was not a pushbutton
     *
     * @since 2.0.7
     */
    public boolean replacePushbuttonField(String field, PdfFormField button, int order) {
        if (getFieldType(field) != FIELD_TYPE_PUSHBUTTON)
            return false;
        Item item = getFieldItem(field);
        if (order >= item.size())
            return false;
        PdfDictionary merged = item.getMerged(order);
        PdfDictionary values = item.getValue(order);
        PdfDictionary widgets = item.getWidget(order);
        for (int k = 0; k < buttonRemove.length; ++k) {
            merged.remove(buttonRemove[k]);
            values.remove(buttonRemove[k]);
            widgets.remove(buttonRemove[k]);
        }
        for (Object element : button.getKeys()) {
            PdfName key = (PdfName)element;
            if (key.equals(PdfName.T) || key.equals(PdfName.RECT))
                continue;
            if (key.equals(PdfName.FF))
                values.put(key, button.get(key));
            else
                widgets.put(key, button.get(key));
            merged.put(key, button.get(key));
        }
        return true;
    }