Window down and wont come up

I have a problem with the left side sliding door window in my vehicle. The window went down all of a sudden. It did not drop, but quietly slid down. I can lift it up with my hands but it slides back down. The power window button seems to work to lower it: its motors makes the familiar sound and it seems to pull the window down. But when I press up, nothing happens, no sound, no movement. Do I need to replace the entire regulator plus motor assembly? Or is some sort of a cable or hook simply came loose that can be tied back up? I do not want to buy the regulator and motor if I do not have to, but I will if that is the issue. I am a handy guy, but I do not know much about cars, so please explain in plain English. Thanks!