[Deff]

<div class="block2"> <object width="100%" object height="100%" align="top" id="videoplayer162">
<param name="allowFullScreen" value="true" />
<param name="allowScriptAccess" value="always" />
<param name="wmode" value="transparent" />
<param name="movie" value="http://nikapress.myds.me/structure/uppod.swf" />
         <param name="flashvars" value="st=http://nikapress.myds.me/structure/style/2560_player.txt&amp;pl=http://nikapress.myds.me/playlist.txt" />
         <embed src="http://nikapress.myds.me/structure/uppod.swf" width="100%" type="application/x-shockwave-flash" height="100%" allowscriptaccess="always" allowfullscreen="true" wmode="transparent" flashvars="st=http://nikapress.myds.me/structure/style/2560_player.txt&amp;pl=http://nikapress.myds.me/playlist.txt" align="top"></embed> </object>
</div>
<script type="text/javascript">
(function() {
var a= window.screen.width;
var b = 2560_player.txt,c;
 var obj=document.getElementById('videoplayer162').getElementsByName('flashvars')[0];
//Условие
if(a>1280&&a<=1440) obj.value=obj.value.replace(b,'1440_player.txt');
//Тут могут быть еще условия;
}())
 </script>