[Javascript] Menu déroulant et Text Area

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<html>
<head>
	<title>Untitled</title>
	<script language="javascript" type="text/javascript">
			function displaySelection(elm){
			  out = document.getElementsByName("output")[0];
			  if(out.value==""){
			    out.value=elm.value;
			  }else{
			    out.value=out.value+"\n"+elm.value;
			  }
			}
	</script>
</head>

<body>

<select name="dataSrc" onchange="displaySelection(this);">
		<option value="HackTrack" />HackTrack
		<option value="Web"/>Web
		<option value="Programming"/>Programming			
</select>

<br/>

<textarea name="output" cols="25" rows="10">
</textarea>

</body>
</html>