-        download_form = dict(re.findall(
-            r'<input type="hidden" name="([^"]+)" value="([^"]*)"', webpage))
-        request = compat_urllib_request.Request(
-            url, compat_urllib_parse.urlencode(download_form))
+        download_form = self._hidden_inputs(webpage)
+        request = sanitized_Request(
+            url, urlencode_postdata(download_form))