Embedded objects: browser dependencies?

I've put together a web application that embeds a couple of other web pages in my page. In Chrome and IE it works fine, but in Firefox it says a missing plugin is required. If I click "Install missing plugin", 开发者_如何学JAVAFirefox is unable to find one. The strange thing is that everything on my page loads fine. Is this a bug in Firefox?

Here is my markup:

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent"> 
    <fieldset id="total">
        <legend>Total Statistics</legend>
        <asp:UpdatePanel ID="UpdatePanel3" runat="server" UpdateMode="Always">
            <ContentTemplate>
                <object data="http://sceedev16/flashboard.html" style="width: 100%; height:400px">
                    <embed src="http://sceedev16/flashboard.html" width="100%" height="400"></embed>
                </object>
                <asp:Timer ID="ui_timer" runat="server" Interval="60000" OnTick="Timer_Tick"></asp:Timer>
            </ContentTemplate>
        </asp:UpdatePanel>
    </fieldset>
</asp:Content>

The <embed> tag is what causes the problem in Firefox. Firefox does not support using documents as the source in the <embed> tag. It will work using only the <object> tag though:

<object data="http://sceedev16/flashboard.html" style="width: 100%; height:400px">
</object>

There are two main options for embedding a document into another. For better browser compatibility and less code I would recommend using an iframe instead:

<iframe src="http://sceedev16/flashboard.html" width="100%" height="400" />

Have you installed Flash/Shockwave plugin installed for firefox?