service.js

function changeGroupState() {
    // Get the button and the slider
    var button = document.getElementById(event.target.id);
    var slider = document.getElementById("slider"+event.target.id);
    var state;

    state = changeButtonState(button);

    var brightness;
    if (state) {
        brightness = 254;
    } else {
        brightness = 0;
    }

    $(("#"+slider.id)).slider('setValue', brightness);

    // Generate URL
    var url = ip+"/hue/group?id="+button.id+"&state="+state

    put(url);
}

/* Put data on the bridge */
function put(url, data) {
	$.ajax({
         type: "POST",
         url: url,
         data: data,
         contentType: "application/json; charset=utf-8",
         crossDomain: true,
         dataType: "json",
      });
}