In this case, i think, you can submit the form to a hidden iframe. just like this:
<iframe name=myIframe width=0 height=0>
.......
<form action="playlist.php" target="myIframe">
.........
of course , if you only want to submit it to a opened small window, try this way: i didn't test it , maybe it would not work. 🙂
<script>
function submitToOpen()
{
window.open('','winName','')
}
</script>
<form action="playlist.php" target="winName">
anyway ,the "target" propertiy is the key.
hope it helped.