The orchid has to be an oncidium purpurescens or some cross of it. Without telling us if it releases a scent, if it has an ocidium bulb structure, and what it flower structure looks like, we can only guess.
Looks like you guys IDed this orchid, but if you're still not sure, or need further identification of orchids, my step dad used to be an orchid judge. Send him an email at [email protected] (that email will change soon) and ask him for assistance. I'm sure he'd help.