in the following javascript code follow the direction below

/* JavaScript 6th Edition Chapter 10 Hands-on Project 10-1

Author: Nick Date: july 27

Filename: script.js */ "use strict";

// global variables var loc = []; var origin; var onTop;

// perform setup tasks when page first loads function setUpPage() { var puzzlePieces = document.querySelectorAll("#pieces div"); onTop = puzzlePieces.length + 1; for (var i = 0; i

// add event listeners and move object when user starts dragging function startDrag(event) { this.style.zIndex = onTop; // set z-index to move selected element on top of other elements onTop++; // increment z-index counter so next selected element is on top of other elements event.preventDefault(); if(event.type !== "mousedown"){ this.addEventListener("touchmove", moveDrag, false); this.addEventListener("touchend", removeTouchListener, false); }else{ this.addEventListener("mousemove", moveDrag, false); this.addEventListener("mouseup", removeDragListener, false); } this.addEventListener("mousemove", moveDrag, false); this.addEventListener("mouseup", removeDragListener, false);

loc = [this.offsetLeft,this.offsetTop]; origin = getCoords(event); }

// calculate new location of dragged object function moveDrag(event) { var currentPos = getCoords(event); var deltaX = currentPos[0] - origin[0]; var deltaY = currentPos[1] - origin[1]; this.style.left = (loc[0] + deltaX) + "px"; this.style.top = (loc[1] + deltaY) + "px"; }

// identify location of event function getCoords(event) { var coords = []; if(event.targetTouches && event.targetTouches.length){ var thisTouch = event.targetTouches[0]; coords[0] = thisTouch.clientX; coords[1] = thisTouch.clientY; }else{ coords[0] = event.clientX; coords[1] = event.clientY; } return coords; }

// remove mouse event listeners when dragging ends function removeDragListener() { this.removeEventListener("mousemove", moveDrag, false); this.removeEventListener("mouseup", removeDragListener, false); } // remove touch event listeners when dragging ends function removeTouchListener(){ this.removeEventListener("touchmove", moveDrag, false); this.removeEventListener("touchend", removeTouchListener, false); }

// run setUpPage() function when page finishes loading if (window.addEventListener) { window.addEventListener("load", setUpPage, false); }