You can do this on two different ways, with static HTML tags <OBJECT
> and <EMBED>, or by embedded Flash video player (this is YouTube's approach). With static HTML here is the code :
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<object classid="clsid:6BF52A52-394A-11d3-B153-00C04F79FAA6" height="280" width="320"
codebase="http://activex.microsoft.com/activex/controls/mplayer/en/nsmp2inf.cab#version=6,4,7,111">
<param name="URL" value="Video/Didi.flv">
<param name="autoStart" value="false">
<param name="UIMode" value="full">
You do not have Windows Media Player installed.
Get it here.
</object>
<object classid="clsid:6BF52A52-394A-11d3-B153-00C04F79FAA6" height="280" width="320">
<param name="URL" value="Video/As%20long%20as%20you%20love%20me.WMV" />
<param name="autoStart" value="false">
<param name="UIMode" value="full">
</object>
</form>
</body>
</html>