1984 Ford Falcon

Well, the other day my friend tried to open my passenger side door to get out, when we heard a crack. After that, we couldn't open the door from the inside anymore. I told him to wind down the window the open the door from the outside, when we heard the sound of glass and metal scraping together. Now the door won't open from the inside and the window is stuck half way down.
I assume a cable has snapped, but I'm really not sure what to do about it.
How would I go about fixing this?

Thanks,
Jayke