The old way: (<embed> tag is obsolete)
<OBJECT classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
 codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=5,0,0,0"
 WIDTH="300px" HEIGHT="300px">
 <PARAM NAME=movie VALUE="SampleFlash.swf"> 
 <PARAM NAME=quality VALUE=high> 
 <PARAM NAME=bgcolor VALUE=#FFFFFF> 
 <EMBED src="SampleFlash.swf" quality=high bgcolor=#FFFFFF  WIDTH=50% HEIGHT=50% 
TYPE="application/x-shockwave-flash" 
PLUGINSPAGE="http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash">
 </EMBED>
</OBJECT>
The new way:
<object type="application/x-shockwave-flash" data="SampleFlash.swf" 
    width="300px" height="300px">
<param name="movie" value="SampleFlash.swf" />
</object>
Youtube:
<object type="application/x-shockwave-flash"
  data="http://www.youtube.com/v/beqxaYYNA10"
  width="400" height="325">
  <param name="movie" value="http://www.youtube.com/v/beqxaYYNA10" />
  </object>