Externalinterface VS Internet Explorer

1

AS3 (part of it)

function clickHandler(event:Event):void{
import flash.external.ExternalInterface;
    if(event.target.name == "button_1"){
        if (container.button_1.selected == true) {
            layer_2.alpha = layer_3.alpha = layer_4.alpha = layer_5.alpha = layer_6.alpha = layer_7.alpha = layer_8.alpha = 1;
            ExternalInterface.call("showDiv", "layer_1");
            ExternalInterface.call("hideDiv", "layer_2");
            ExternalInterface.call("hideDiv", "layer_3");
            ExternalInterface.call("hideDiv", "layer_4");
            ExternalInterface.call("hideDiv", "layer_5");
            ExternalInterface.call("hideDiv", "layer_6");
            ExternalInterface.call("hideDiv", "layer_7");
            ExternalInterface.call("hideDiv", "layer_8");            
            
        } else {            
            layer_5.alpha = 0;
            layer_6.alpha = 0;
            ExternalInterface.call("hideDiv", "layer_1");
        }
        
    }
..................etc..............

HTML

<script type="text/javascript">
    var flashvars = {};
    var params = {};
    params.allowscriptaccess = "always";
    var attributes = {};
    attributes.id = "flash";
    swfobject.embedSWF("main_v3.swf", "flash", "650", "400", "8.0.0", "expressInstall.swf", flashvars, params, attributes);
</script>


<script type="text/javascript">
    function hideDiv(class)
    {
            $("."+class).fadeOut("slow");
    }
    function showDiv(class)
    {
            $("."+class).fadeIn("slow");
            $('html,body').animate({scrollTop: $("#box2").offset().top},'slow');
    };
</script>
<div class="flash_wrapper">
<div id="flash">
            <a href="http://www.adobe.com/go/getflashplayer">
                <img src="http://www.adobe.com/images/shared/download_buttons/get_flash_player.gif" alt="Get Adobe Flash player" />
            </a>
        </div>
</div>
<p id="box2"></p> 
<div class="layer_1 hidden">test contetn</div>

this code works fine (show/hide divs) in firefox, opera, chrome… but not in Internet explorer.

please, help!