dialog: no nested dialogs? is this good to change $.ui.dialog.prototype._init = function() ? what if jQ people rename this "undoc" prop "_init" ? http://net.tutsplus.com/tutorials/javascript-ajax/creating-a-windows-like-interface-with-jquery-ui/ Conclusions: jq kills top array in paper, but clones in subnode. null from paper is preserved undefined from paper is removed undefined from wall is preserved