Update someone's status

Hello,

I tried to update a friend's status (he's aware of that, it's like a competition between us). To do that, I use "Live HTTP Headers" and "Tamper Data" extensions for Firefox.

Once I get the initial $_POST with Live HTTP Headers. I use the following fonction (found here), to get the phstamp variable.
Finally, I post a new status on my own wall using Tamper Data and I change the $_POST['xhpc_targetid'], $_POST['xhpc_message_text'], $_POST['xhpc_message'], $_POST['__user'] and $_POST['phstamp'].

I know that my phstamp number is good, I have the same value for original post.

The problem is it doesnt work. Any suggestion?
Maybe the fb_dtsg could be the problem, or the composer_session_id.

I also tried to make a friend to like a fanpage, there is no session_id and it doesnt work either.

So what is the fb_dtsg?

Thank you in advance.


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function generatePhstamp(qs, dtsg) {
var input_len = qs.length;
numeric_csrf_value='';

for(var ii=0;ii<dtsg.length;ii++) {
numeric_csrf_value+=dtsg.charCodeAt(ii);
}
return '1' + numeric_csrf_value + input_len;
}

var qs = 'fb_dtsg=AQBtHA-j&postfromstub=true&xhpc_targetid=FACEBOOK_ID&xhpc_context=home&xhpc_ismeta=1&xhpc_fbx=1&xhpc_timeline=&xhpc_composerid=ushs0ph1&xhpc_message_text=NEW_STATUS&xhpc_message=NEW_STATUS&is_explicit_place=&composertags_place=&composertags_place_name=&composer_session_id=1349048846&postfromfull=true&composertags_city=&disable_location_sharing=false&composer_predicted_city=&audience[0][value]=40&nctr[_mod]=pagelet_composer&__user=FACEBOOK_ID&__a=1';

var dtsg = 'AQBtHA-j';
var ret = generatePhstamp(qs,dtsg);
document.write(ret);

Yes fb_dtsg is an anti-CSRF token.

You may have seen these back in the day ... http://www.symantec.com/connect/blogs/please-send-me-your-facebook-anti-csrf-token