You can't use onactivate with div - it doesn't support it.
The only attributes it supports are:
id, class, lang, dir, title, style, align
And
onclick, ondblclick, onmousedown, onmouseup, onmouseover, onmousemove, onmouseout, onkeypress, onkeydown, onkeyup
See the HTML5 spec:
4.4 Grouping content — HTML5[
^]