What are these pants called?

I really like this girl's billie jean outfit in the following video: http://www.youtube.com/watch?v=zjGtTUfPcI4 You can see what her outfit looks like at 2:51 of this video. I just ordered the jacket which I am hoping will look closest to this girl's in the video but I am still not able to find the pants. Mainly because I am not sure what these pants are called. Can anyone please tell me the official name of these pants so then I can search them online. I know they are dress pants but thats not enough information. Will be very thankful!