append data from .cs to aspx

I have a page that recieves an id number (ex page.aspx?id=1),
described in its .cs as   string id = Request.QueryString["id"];
I want to append this into my video player
<script type='text/javascript'>
jwplayer('mediaspace').setup({
'flashplayer': '../player.swf',
 'file': 'playvideo.aspx?itemid=ID HERE
'controlbar': 'bottom',
'width': '470',
'height': '320',
'provider': 'http'
});
</script>
 so that this id appends onto the url in the player... I did something similar with repeaters, but this does not use a repeater, its only one video player...
...