But I never would. I never choose to use JS in such a way that it would impede SEO. You can use JS for a flyout menu without impeding SEO in the slightest, you just can't append the document on the fly. As for popup windows, I never use those either, so it's not really a problem. If I do, I use the _blank method. I would sooner hide/show a div that is absolutely positioned, than open a new window.