javascript 怎么取得form内flash的名字

<SCRIPT type=text/javascript>
<!--

var focus_width=264
var focus_height=195
var text_height=0
var swf_height = focus_height+text_height

var pics='http://image2.sina.com.cn/edu/U602P42T143D1F3567DT20051205200851.jpg|http://image2.sina.com.cn/edu/U602P42T143D1F3563DT20051122183108.jpg|http://image2.sina.com.cn/edu/U602P42T143D1F3569DT20051209191716.jpg|http://image2.sina.com.cn/edu/U602P42T143D1F3565DT20051208191517.jpg|http://image2.sina.com.cn/edu/U602P42T143D1F3561DT20051201181540.jpg'
var links='http://edu.sina.com.cn/kejian|http://edu.sina.com.cn/z/kaoyanEnglishCcontest.html|http://forum.edu.sina.com.cn/cgi-bin/viewone.cgi?gid=40^fid=1130^itemid=22454|http://edu.sina.com.cn/en/2005-12-08/113935217.html|http://edu.sina.com.cn/z/2006kyzyk/index.html'
var texts='||||'

document.write('<object id="obj1" classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,0,0" width="'+ focus_width +'" height="'+ swf_height +'">');
document.write('<param name="allowScriptAccess" value="sameDomain"><param name="movie" value="http://image2.sina.com.cn/tn/pixviewer.swf"><param name="quality" value="high"><param name="bgcolor" value="#ffffff">');
document.write('<param name="menu" value="false"><param name=wmode value="opaque">');
document.write('<param name="FlashVars" value="pics='+pics+'&links='+links+'&texts='+texts+'&borderwidth='+focus_width+'&borderheight='+focus_height+'&textheight='+text_height+'">');
document.write('<embed src="http://image2.sina.com.cn/tn/pixviewer.swf" wmode="opaque" FlashVars="pics='+pics+'&links='+links+'&texts='+texts+'&borderwidth='+focus_width+'&borderheight='+focus_height+'&textheight='+text_height+'" menu="false" bgcolor="#ffffff" quality="high" width="'+ focus_width +'" height="'+ focus_height +'" allowScriptAccess="sameDomain" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" />'); document.write('</object>');
function f1()
{
alert(document.all.obj1.object.Movie);
}
//-->

</SCRIPT>
<input type="button" onclick="f1()">