Element resizable

HTML

<div id="element">Element resizable
<div class="resizer">

</div></div>

SCSS

div {
  position: relative;
  float:left;
  overflow: hidden;
  background: blue;
  width: 200px;
  .resizer{
    position:absolute;
    width:100%;
    bottom:0;
    height:10px;
    cursor:s-resize;
    background-color:red;
  }
}
#element {
  position: relative;
  overflow: hidden;
  background: green;
  min-height: 100px;
  width: 200px;
 }

JavaScript

var element = document.getElementById('element');
var resizer = document.getElementsByClassName('resizer');
resizer[0].addEventListener('mousedown', initResize, false);

function initResize(e) {
   window.addEventListener('mousemove', Resize, false);
   window.addEventListener('mouseup', stopResize, false);
}

function Resize(e) {
   element.style.height = (e.clientY - element.offsetTop) + 'px';
   console.log('yes')
}

function stopResize(e) {
    window.removeEventListener('mousemove', Resize, false);
    window.removeEventListener('mouseup', stopResize, false);
}