protected function _get_input_html(array $params = array())
 {
     $html = parent::_get_input_html($params);
     $html .= new HTMLScriptTag("\$(" . JSHelper::cast_str('#' . $this->_get_id()) . ").bind('change', function() { \$(this).val(String(\$(this).val()).replace(/[^\\d\\.\\-\\,]/g, '')); });");
     return $html;
 }