Dynamically add/remove select boxes depending on value of other select box

[mEdensky]

Here's what I want to achieve - at the bottom of this page you can change number of rooms ("Antal rum") and the quantity of select boxes for how many people go in to each room (one select box for each room) is updated:
http://www.bokahotell.se/offers.aspx?req_action=53&loc_intid=8027

What would be the best, cleanest way of achieving this? Which direction should I go?

[mEdensky]

I just solved it. It was a lot simpler than how I first thought.

In the html I loaded all peoplePerRoom-boxes and put hidden="true", and at the onChange of the room quantity box I put a function that checks the value, and through a for-loop changes the hidden-value for the peoplePerRoom-boxes accordingly.

Initially I was thinking along the lines of saving the quantity of rooms as a $_SESSION etc 😃.