JavaScript ñ roda no ff pq?

<script language="Javascript">

 if (screen.width <= 900) {

 document.write('')

 }

 if (screen.width >= 901) {

 document.write('<td style="padding-top:0px;padding-bottom:0px;" height="590"><td>\n');

 document.write('<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="[http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,19,0"](http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,19,0) width="187" height="553">\n');

 document.write('<param name="movie" value="/imagens/flash/1024.swf">\n');

 document.write('<param name="quality" value="high">\n');

 document.write('<embed quality="high" pluginspage="[http://www.macromedia.com/go/getflashplayer"](http://www.macromedia.com/go/getflashplayer) type="application/x-shockwave-flash" width="187" height="553" ></embed>\n');

 

 }

 </script>

Bom, esse código sempre rodou no IE , mas agora no FF só fica uma tela em branco!

pq, alguém saberia me responder? http://forum.imasters.com.br/public/style_emoticons/default/upset.gif