//Try writing a simple progress bar function in the callback style. Your function should take three callbacks,
//onStart, onProgress, and onEnd as arguments. When you call the function it should call the onStart callback,
//then loop from 1 to 100, using console.log to print each value. Every 10 items it counts it should call the
//onProgress callback, providing how far along it is as an argument. Finally it should call the onEnd callback.

function progressBar(callback1, callback2, callback3){
  callback1();
  for(var i =0; i<=100; i++){
    console.log(i);
    callback2(i);
  }
  callback3();
}

var onStart = function(){
  console.log("start");
}

var onEnd = function(){
  console.log("end");
}

var onProgress = function(num){
  if(num%10 === 0 && num!= 0){
    console.log("counted ten more, till "+num);
  }

}

progressBar(onStart, onProgress, onEnd);