Call particle functions and get particle variables from a device in javascript

nrobinson2000-particle.js

var token = "YOUR_PARTICLE_ACCESS_TOKEN";
var device = "YOUR_PARTICLE_DEVICEID";

function httpPost(url, params)
{
  var xhr = new XMLHttpRequest();
  xhr.open("POST", url, true);

  //Send the proper header information along with the request
  xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  xhr.setRequestHeader("Authorization", "Bearer " + token);
  xhr.send(params);
}

function httpGet(url)
{
    var xhr = new XMLHttpRequest();
    xhr.open("GET", url, false); // false for synchronous request
    xhr.send( null );
    return xhr.responseText;
}

function callFunction(functionName, args)
{
  var params = 'arg=' + args;
  console.clear();
  httpPost("https://api.particle.io/v1/devices/" + device + "/" + functionName, params);
  console.log("Called function: "+ functionName);
  console.log("On device: " + device);
  console.log("With arguments: " + args);
}

function getVariable(variableName)
{
  obj = JSON.parse(httpGet("https://api.particle.io/v1/devices/" + device + "/" + variableName + "?access_token=" + token));
  return obj.result;
}

Hi, Mr. Robinson
Thanks for sharing your good work
How about some advice on how to use this particular .JS file for people who are new to javascript and HTML
and where this line [[ callFunction("test1", '{"onH":1,"onM":35,"offH":2,"offM":55) ]] should be located within HTML