Transparent background

I cant seem to get a transparent background on the buttons I am making and I cant seem to figure out why could someone please help shed some light on my problem?

heres the code:

<!--url's used in the movie-->
<!--text used in the movie-->
<!-- saved from url=(0013)about:internet -->
<script language="javascript">
    if (AC_FL_RunContent == 0) {
        alert("This page requires AC_RunActiveContent.js.");
    } else {
        AC_FL_RunContent(
            'codebase', 'http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0',
            'width', '281',
            'height', '74',
            'src', 'main_nav',
            'quality', 'high',
            'pluginspage', 'http://www.macromedia.com/go/getflashplayer',
            'align', 'middle',
            'play', 'true',
            'loop', 'true',
            'scale', 'showall',
            'wmode', 'transparent',
            'devicefont', 'false',
            'id', 'main_nav',
            'bgcolor', '#ffffff',
            'name', 'main_nav',
            'menu', 'true',
            'allowFullScreen', 'false',
            'allowScriptAccess','sameDomain',
            'movie', 'main_nav',
            'salign', ''
            ); //end AC code
    }
</script>
<noscript>
    <object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="281" height="74" id="main_nav" align="middle">
    <param name="allowScriptAccess" value="sameDomain" />
    <param name="allowFullScreen" value="false" />
    <param name="movie" value="main_nav.swf" /><param name="quality" value="high" /><param name="wmode" value="transparent" /><param name="bgcolor" value="#ffffff" />    <embed src="main_nav.swf" quality="high" wmode="transparent" bgcolor="#ffffff" width="281" height="74" name="main_nav" align="middle" allowScriptAccess="sameDomain" allowFullScreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" />
    </object>
</noscript>

here the .fla and the .swf of the buttons:
http://www.arctosdesign.com/main_nav.fla
http://www.arctosdesign.com/main_nav.swf
I want to use them on my web page in
Dreamweaver but I cant do that because there is a beautiful white background that gets in the way even when I remove all the “bg=”#fff"" or similar from the code. would really appreciate the help thanx.