Subject: How does a flute work?

How does a flute work?  I guess it has something to do with why a bottle 
"whistles" when you blow over it (btw, how does *that* work) but how does 
changing the finger placements work?  And why does there have to be a hole 
before the finger holes?  And, last one I promise, is there any difference in 
how the side flute (like the concert flute) works versus the one that's held 
straight (like the pan flute).  Much obliged!

Re: How does a flute work?