Screamer,
<html>
<head>
<title>JS</title>
<style>
#tracklist {
padding: 2px;
margin: 2px;
border: 1px dotted black;
}
a, span {
text-decoration: none;
color: red;
cursor: pointer;
}
</style>
<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("span#plus").click(function(){
var content = '<div><input type="text" name="tracklist[]" value="" /> <span onclick="$(this).parent...remove()">-</span></div>'
$("div#tracklist").append(content);
});
});
</script>
</head>
<body>
<form method="post" action="">
<div id="tracklist">
<div><input type="text" name="tracklist[]" value="" /></div>
</div>
<div style="text-align:center;">
<span id="plus">+</span>
</div>
</form>
</body>
</html>