rollbar_error.js

    var button = document.createElement("button");
	button.innerHTML = "Create an error";

	var body = document.getElementsByTagName("body")[0];
	body.appendChild(button);

	function multiplication(n1, n2) {
		try {
			throw "blah";
		} catch(err) {
			alert("I am an error message")
		}
		return n1 * n2;
	} 

	function numero(num) {
		try {
  			throw new Error("Something went wrong inside numero");
		} catch (e) {
  			Rollbar.error(e);
		}
		return num;
	}

	button.addEventListener ("click", function() {
  		console.log(multiplication(numero(2), 4));
	});


	function myFunction() {
	  var message, x;
	  message = document.getElementById("p01");
	  message.innerHTML = "";
	  x = document.getElementById("demo").value;
	  try {
	    if(x == "") throw "empty";
	    if(isNaN(x)) throw "not a number";
	    x = Number(x);
	    if(x < 5) throw "too low";
	    if(x > 10) throw "too high";
	 	}
  		catch(err) {
    		message.innerHTML = "Input is " + err;
  		}
	}

	try {
  		throw new Error("Something went wrong");
	} catch (e) {
		console.log('This is challenging but I like challenges')
  		Rollbar.error(e);
	}