<html xmlns="http://www.w3.org/1999/xhtml"> <head> <bindings xmlns="http://www.mozilla.org/xbl"><binding id="x"><content><caption xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"><children xmlns="http://www.mozilla.org/xbl"/></caption></content></binding></bindings> </head> <body onload="document.getElementById('y').innerHTML = '9';"> <span id="y" style="-moz-binding: url(#x)"><div style="border: 5px solid green">123</div></span> </body> </html>