How can I properly rig a model? [closed]

I created a model of a deer and wanted to animate that, but for some reason I can't bend the legs, even though I rigged it. I read names are pretty important, but it doesn't matter how I call it, it just keeps acting weird:

http://i64.tinypic.com/fn4nps.png

the rig:

http://i64.tinypic.com/nyh2xv.png

the names:

http://i66.tinypic.com/dyam1k.png

Can someone please explain why this happens?