var params = {
    "method": "get_session_key",
    "params": {
        "username" : "admin",
        "password" : "test"
    },
    id: 1,
    jsonrpc: "2.0"
};
 
 
$.ajax({
    url: "http://LimeSurvey/index.php/admin/remotecontrol",
    type: "POST",
    contentType: "application/json",
    data: JSON.stringify(params),
    error: function(data) {
        console.log('error');
        console.log(data);
    },
    success: function(data) {
        console.log('success');
        console.log(data);
    }
});

Accept	*/*
Accept-Encoding	gzip, deflate
Accept-Language	en-US,en;q=0.5
Content-Length	83
Content-Type	application/json; charset=UTF-8
Host	10.0.0.2
Referer	http://10.0.0.2/www/
User-Agent	Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:19.0) Gecko/20100101 Firefox/19.0
X-Requested-With	XMLHttpRequest
 
 
POST body:
{"method":"get_session_key","params":{"username":"admin","password":"test"},"id":1}

Cache-Control	no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Connection	Keep-Alive
Content-Encoding	gzip
Content-Length	20
Content-Type	text/html
Date	Tue, 19 Mar 2013 15:23:41 GMT
Expires	Thu, 19 Nov 1981 08:52:00 GMT
Keep-Alive	timeout=15, max=99
Pragma	no-cache
Server	Apache/2.2.16 (Debian)
Vary	Accept-Encoding
X-Powered-By	PHP/5.3.3-7+squeeze15