function buildRequestFormHTML($params, $method = 'post', $target = '_self')
{
$params = $this->buildSignedParameters($params);
$html = '<meta charset="' . $this->config['input_charset'] . '" /><form id="alipaysubmit" name="alipaysubmit" action="' . $this->gateway . ' _input_charset="' . trim(strtolower($this->config['input_charset'])) . '" method="' . $method . ' target="$target">';
foreach ($params as $key => $value) {
$html .= "<input type='hidden' name='{$key}' value='{$value}'/>";
}
$html .= "</form><script>document.forms['alipaysubmit'].submit();</script>";
return $html;
}