How to send pramas through post function in jquery?

I got javascript code which use jquery to activate function with $.post. I want to send string parameter to that function, unsuccessfully.

i try this function call i saw on other post, but it didn't work $.post(SavePoint, { data });

myTimer = (function(ctx) {
  $.post(getPoint).done(function(xml) {
    parseXml(xml);

    var lon = (parseFloat($xml.find("lon").text()) + 180) * (screen.height / 360);
    var lat = (parseFloat($xml.find("lat").text()) + 90) * (screen.width / 180);

    draw(ctx, rout, lat, lon);

    if (recordTime <= 0 && recordTime > -0.2) {
      $.post(SaveToFile);
      isSaveNeeded = "false";
    }

    var isSaveNeeded = document.getElementById("isSaveNeeded").value;
    if (isSaveNeeded == "true") {
      var latS = parseFloat($xml.find("lat").text());
      var lonS = parseFloat($xml.find("lon").text());
      var rudderS = parseFloat($xml.find("rudder").text());
      var throttleS = parseFloat($xml.find("throttle").text());

      var data = latS + "," + lonS + "," + rudderS + "," + throttleS + ",";      
      alert(data);

      $.post(SavePoint, {
        data
      }); //This func call doesn't work..

      alert(data);
      recordTime -= 0.25;
    }
  });
});

setInterval(function() {
  myTimer(ctx);
}, 1000 / rate);