IE Behaviour demos and span.js demo don't work in IE9

[jayfresh]

To reproduce:

• open both IE Behaviour demos or the span.js demo in IE9
• observe the inputs are empty

I note that if I switch the browser into compatibility mode, the inputs are filled, but then you get a JavaScript error: "Unable to set value of the property 'innerHTML': object is null or undefined" (line 98, character 4)

So only the simple.js demo works in IE9.