Orchid wilting

Hi, I'm brand new to plants...I bought an orchid in bloom about month ago. I repotted it when I got it. It has been doing well until now. The flowers are now wilting on one of the spikes. A couple of them are dry and papery. The other spike looks good and even has 1 bud on it, and the leaves are bright green. It has been sitting underneath a high southeast window. Definitely indirect light, and I've been worried it may not be enough. I have watered it every 10 days and I let it drain well. I haven't given it any fertilizer/orchid food. The climate here is becoming quite cold, if that is relevant in any way. Is it just at the end of it's blooming cycle? Or since it still has a bud does that mean instead that something is wrong and it's not happy? Do I cut the spike with the wilted flowers now? Or do I just cut the flowers at the base of their stems?

It's probably just the end of its blooming cycle but a picture of the plant could help.

Here are some pictures. The bud that was on the good spike died :(.

I'll try that again.

I agree with Plantfreak re the plants life cycle, I also think the flowers dying off are because they have done flowering for this season, yes you have another stem with buds, but after that set of flowers die down, then remove the stems as they die down, leave the foliage alone and keep dust free as leaves covered in dust cant breath.

You never said when you re-potted the plant, did you use an Orchid soil specially suited for these plants, also while in bloom, I think you would be requiring to water more often than 10 day intervals as the flowering stage means the plant (ALL plants) use up a lot of energy and a half strength Orchid plant feed would be good too.

I note there is a toilet close to where the plant is situated, IF this room gets plenty light, I would set the plant inside that room as the steam and humid atmosphere is exactly what these plants like in the GROWING season, that's from about spring to end of summer.

When you buy plants in future for INDOORS only, don't re-pot for a few weeks so the plant has time to get settled into it's new environment, after you note it is happy, then go ahead and re-pot only IF required, too large a pot is as bad as too small a pot, on small plants (ROOT SIZE OF SMALL, it's never good to put them into a large pot as the extra soil required means the roots are sitting in too much wet soil and because the pot and soil is over sized, this can cause the roots to rot. Always just move up maybe 2 sizes of pot and make sure there is a drainage hole in bottom, remove any excess water from saucers at the base.
IF you cant get a humid atmosphere for your lovely plant, every couple of weeks, give the plants foliage a misting with TEPID water and do the underside of foliage too, this keeps dust away and it helps give some humidity around the foliage, in summer months increase the misting to every few days.
Hope all this is a help for you and you can really enjoy many years with your Orchid, by the way, they do thrive on a little neglect once they are a few years old.
Best Regards.
WeeNel.