thank you Joshua
it's a little help, but not the solution I'm looking for
the problem is that the aside menu on some mobile browser (I said Opera and Firefox) automatically closes when the bottom limit is reached
what I'd like it to do, is that when I scroll down until the bottom end of the aside menu, it doesn't close itself, but just stops scrolling remaining opened, as it happens using for example Chrome on Android
the solution you are suggesting increases a little bit the usability, but doesn't solve the question I'd like to
I hope I've explained clearly what I mean; if not, tell me and I'll try to do it better
thanks again