IFTTT Webhook Button Bookmarklet

javascript:
    var http = new XMLHttpRequest();
    var url = "https://maker.ifttt.com/trigger/{event}/with/key/{key}";
    http.open("POST", url, true);
    http.send(JSON.stringify({"value1": "test"}));

Is this working for you? I can use the bookmarklet and it will trigger IFTTT, but my result is lacking value1. I am trying to send the URL of the actual website to IFTTT and from there to a trello-like tool called meistertask.
So, is value1 working for you?