<param name="wmode" value="transparent">
と設定するだけで透明になります。
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,28,0" width="400" height="300" title="mymovie"> <param name="movie" value="swf/sample.swf" /> <param name="quality" value="high" /> <param name="wmode" value="transparent"> <embed src="swf/sample.swf" quality="high" pluginspage="http://www.adobe.com/shockwave/download/download.cgi?P1_Prod_Version=ShockwaveFlash" type="application/x-shockwave-flash" width="400" height="300" wmode="transparent"></embed> </object>
<object data="swf/sample.swf" type="application/x-shockwave-flash" id="some-movie" width="400" height="300"> <param name="movie" value="swf/sample.swf" /> <param name="wmode" value="transparent"> </object>
代替コンテンツ
<script type="text/javascript" src="_common/js/swfobject.js"></script>
<script type="text/javascript"> //params用の引数のオブジェクトを設定
var params = {
wmode: "transparent"
};
//8個目の引数にparamsを設定する
swfobject.embedSWF("swf/sample.swf", "myContent", "400", "300", "9.0.0","","",params);
</script>
Flash上で文字入力をさせる場合、透明化させているとWindowsで不具合がでます。