how do I insert html into a window? This doesn't seem to work:
You have four problems here:
2) "doesn't seem to work" -- http://catb.org/~esr/faqs/smart-questions.html
var testwindow = window.open ("", "mywindow",
var el = testwindow.document.createElement('div');
3) creating an element doesn't insert it into the DOM
el.innerHTML = content;
4) content is apparently undefined.