Quello completo è così:

codice:
<object
	classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
	codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0"
	width="550" height="413">
	<param name="movie" value="foto.swf">
	<param name="quality" value="high">
	<param name="FlashVars" value="img=<%=img%>">
	<embed
		src="foto.swf"
		FlashVars="img=<%=img%>"
		quality="high"
		pluginspage="http://www.macromedia.com/go/getflashplayer"
		type="application/x-shockwave-flash"
		width="550" height="413">
	</embed>
</object>
e ti ritrovi semplicemente la variabile "img" a livello della timeline principale.