flash层置底的写法
设置flash的div层置底，需要加入HTML代码：
<param name="wmode" value="opaque" />
此方法是兼容IE可行，在FF下失效。
但是只加这个代码，IE可行，在FF下，失效。要想在FF下起作用，还要用在<object><embed 参数加个 wmode="opaque" ，
<object id="flashobj" classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=5,0,0,0" width="1024" height="768"><param name="allowScriptAccess" value="sameDomain" ><param name="movie" value="flash/fl.swf"><param name="quality" value="high"><param name="bgcolor" value="#fffff"><param name="menu" value="false"><param name="wmode" value="transparent"><embed src="flash/fl.swf" wmode="opaque" menu="false" bgcolor="#fcfcfc" quality="high" width="1024" height="768" allowscriptaccess="sameDomain" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" name="flashobj"></object>
<param name=movie value="b.swf"> <param name=quality value=high> <embed src="b.swf" quality=high width=1024 height=768 type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash" name="flashobj" swLiveConnect="true"> </embed>
