Driver side wiper stopped working

I was on the way to work today and it was raining...turned the wiper on and next thing I know, driver side wiper flops off the edge of my window. Then I realize...the wiper is loose..as in I can move it back and forth at will...the passenger side is fine.

Question 1, what's broken the motor or the arm?
Question 2, can I fix it myself

Question 3, how much will this cost me?

Sorry I don't frequent this part of AF too often, what year is your car?

I just got through replacing the entire wiper assembly on my '88 because of a little tab that broke where the wiper arm attaches. Similar sounding problem to yours. But if your car is newer you might just have a nut holding the arm down, which you can usually just tighten back up.

Its a 94... Is that new enough for the nut tightening?

Uhhh i'm not sure, got any pictures of it? Is there a nut at the bottom of the wiper arm? (there's usually a cover that either pops off or folds back over top of the nut)

http://shbox.com/1/wiper_motor.jpg

Can't tell if it's the nut kind, but there's your wiper assembly. It does look like the nut kind, but can't be sure from that diagram.

soo...how do i get the wiper off to tighten it?

The wiper has a cover that pops off the bottom part. Then you remove the nut (only if you plan on removing it) then pry it off the drive gear. If the gear is spinning back and forth but the wiper isn't moving. You might have stripped some teeth on either end as well.