Pick the pot up and check the saucer underneath it. If there is standing water in the saucer, you have overwatered the orchid. Feel the potting mix. If it is soggy, that is another indication that you have overwatered.
Dump out the soggy potting mix and look at the roots. Rotted roots from severe overwatering will be black, gray or mushy.
Remove the orchid from its container. Dip a knife in alcohol to sterilize it, and use it to cut off any rotted roots. If there are no rotted roots, brush off as much of the soggy potting mix as you can.
Lower the orchid into a new pot that has drainage holes. Fill the pot with orchid potting bark. Place three ice cubes on top of the bark to water it.