The problem is that you replaced the player URL (highlighted in blue below) with the URL of your flv file... try changing it back.
code:
<script type="text/javascript" src="https://media.dreamhost.com/ufo.js"></script>
<p id="sample.flv"><a href="http://www.macromedia.com/go/getflashplayer">Get the Flash Player</a> to see this player.</p>
<script type="text/javascript">
var FO = { movie:"https://media.dreamhost.com/mediaplayer.swf",width:"320",height:"240",majorversion:"7",build:"0",bgcolor:"#FFFFFF",
flashvars:"file=https://media.dreamhost.com/sample.flv&showdigits=true&autostart=false" };
UFO.create(FO,"sample.flv");
</script>
You could also upload a flash video player to your own site if you don't want to use DreamHost's copy.
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