<html>
<head>
</head>
<body>
<textarea id="isert"></textarea>
<select onchange="fn(this)">
<option value="insert test 1">1</option>
<option value="insert test 2">2</option>
</select>
<script>
var ta = document.querySelector('textarea');
function fn(ths) {
ta.innerHTML += ths.value + '\n';
}
</script>
</body>
</html>