upps. The I copied to less from my python code. Sorry !

data='';  data = json.dumps(data).encode('utf-8')
headers = {'__atts' : ajax_atts,  '__ath' : ajax_ath,  '__atcrv' : aja
+x_atcrv }      
req = urllib.request.Request(url2)
req.data = data; 
req.headers = headers;

f = urllib.request.urlopen(req)
[download]