API renren.com with nodejs

i need to call like.getCount from the renren.com API i can't understand chinese and with google translator i can't fully understand how to make the call i have already this code in nodejs but it doesn't work:

var postdata='[{"v":"1.0","call_id":"1333106764755", "urls":urltest}]' ;
var finalurl = 'http://api.renren.com/restserver.do';
request({  url: finalurl ,  headers: default_headers,  method: 'POST',  body: postdata},
function(error, response, body) {

    var result= JSON.parse(body);

    console.log(result);
});

Someone can help me pls?

I have this code:

var postdata='[{"v":"1.0","call_id":"1333106764755","method":"like.getCount", "urls":'+urltest+'}]' ;
var finalurl = 'http://api.renren.com/restserver.do';
var default_headers = { 'Content-type': 'application/json' };

request({  url: finalurl ,  headers: default_headers,  method: 'POST',  body: postdata},
function(error, response, body) {
    console.log(body);
});

i always get error_code=101 , error_msg=???api_key??????????, is there an easy way to call this ren api? like in Facebook or twitter maybe using a nodejs module or something?