How to get the event.target on drop in javascript

var randomIndex;
var array2 = [];
var item;
var tempimages = [];
var notesselected = [];

var items = [{
  label: '1',
  url: 'https://via.placeholder.com/150x150.jpg?text=image1'
 }, {
  label: '2',
  url: 'https://via.placeholder.com/150x150.jpg?text=image2'
 }, {
  label: '3',
  url: 'https://via.placeholder.com/150x150.jpg?text=image3'
 }, {
  label: '4',
  url: 'https://via.placeholder.com/150x150.jpg?text=image4'
 }, {
  label: '5',
  url: 'https://via.placeholder.com/150x150.jpg?text=image5'
 }, {
  label: '6',
  url: 'https://via.placeholder.com/150x150.jpg?text=image6'
 }, {
  label: '7',
  url: 'https://via.placeholder.com/150x150.jpg?text=image7'
 }, {
  label: '8',
  url: 'https://via.placeholder.com/150x150.jpg?text=image8'
 }, {
  label: '9',
  url: 'https://via.placeholder.com/150x150.jpg?text=image9'
 }
];

var notes = [
 'https://via.placeholder.com/75x75?text=1',
 'https://via.placeholder.com/75x75?text=2',
 'https://via.placeholder.com/75x75?text=3',
 'https://via.placeholder.com/75x75?text=4', 'https://via.placeholder.com/75x75?text=5',
 'https://via.placeholder.com/75x75?text=6',
 'https://via.placeholder.com/75x75?text=7',
 'https://via.placeholder.com/75x75?text=8',
 'https://via.placeholder.com/75x75?text=9'
];

array2 = items.slice();
notes2 = notes.slice();

boxtags = document.getElementsByClassName("box");

function rvalue() {

 for (var index = 0; index < 3; index++) {
  randomIndex = Math.floor(Math.random() * array2.length)

   item = array2[randomIndex];

  tempimages.push({
   data: item,
   index: randomIndex
  });
  notesselected.push({
   data: notes2[randomIndex],
   index: randomIndex
  });

  boxtags[index].style.backgroundImage = 'url(' + item.url + ')';

  array2.splice(randomIndex, 1);
  notes2.splice(randomIndex, 1);
 }
}

function allowDrop(ev) {
 ev.preventDefault();
}

function drag(ev) {
 ev.dataTransfer.setData("Text", ev.target.id);
}

function drop(ev) {

 ev.preventDefault();
 var data = ev.dataTransfer.getData("Text");
 var el = document.getElementById(data);

 var x = document.getElementById("slide").dataset.itemIndex;
 var y = '';
  console.log('typeof tempimages[x]');
  console.log(typeof tempimages[x]);

 if (typeof tempimages[x] !== 'undefined') {
   y = tempimages[x].index;
 }

 console.log(x);
 console.log(y);
 if (x == y) {
  console.log('right place');
  ev.currentTarget.style.backgroundColor = 'initial';
  ev.currentTarget.style.backgroundImage = 'initial';
  ev.currentTarget.style.border = 'initial';

  var pParagraph = ev.currentTarget.firstElementChild;
  pParagraph.style.visibility = "hidden";
  item = this.item;
  var arrayvalue = item.dataindex;
  tempimages.splice(arrayvalue, 1);
  if (tempimages.length == 0) {
   rvalue();
  }
  displayAllImages();
 } else {
  console.log('wrong place');
 }

 

 //}
}
function displayAllImages() {
 if (tempimages.length == 0) {
  rvalue();
 }

 var arr2 = notesselected;
 item = arr2.shift();
 image = document.getElementById('slide');
 image.src = item.data;
 image.dataset.itemIndex = item.index;
}

$(function () {

 displayAllImages();

});

.box {
  width: calc(33.3% - 4px);
  display: inline-block;
  border-radius: 5px;
  border: 2px solid #333;
  margin: -2px;
  border-radius: 0%;
}

.box {
  height: 15vh;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  background-size: contain;
}

.box002 {
  position: absolute;
  top: 25.3vh;
  left: 40.98vw;
  cursor: pointer;
}

.box002 img {
  width: 14.0vw;
  height: 23.0vh;
  border-radius: 50%;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="container2">
<div class="containerr">
<div class="pic" id="content">
<div id="container">


<div class="box" ondrop="drop(event)" ondragover="allowDrop(event)" id="10">
 <p name="values"></p>
</div>
<div class="box" ondrop="drop(event)" ondragover="allowDrop(event)" id="11">
 <p name="values"></p>
</div>
<div class="box" ondrop="drop(event)" ondragover="allowDrop(event)" id="12">
  <p name="values"></p>


</div>
</div>
</div>
</div>
</div>


<div class="box002" draggable="true" ondragstart="drag(event)" id="2">
  <img src="" draggable="true" id="slide" border="rounded" />
</div>