<html>
<head>
</head>
<body>
<script>
function dump(text) {
  document.getElementById('clicked').innerHTML = text;
}
</script>
<div style='overflow: scroll; width: 150px; height: 200px; background-color: yellow' id="outer">
  <div style="width: 150px; height: 5000px; background-color: red;" onclick="dump('clicked')" id="inner">
  </div>
</div>
<div>
Clicked: <span id='clicked'></span>
</div>
</body>
</html>