What is it to have knowledge?

What is it to have knowledge? When does belief become truth? What are the requirements to say that someone knows such and such? They seem like simple questions but they really aren't. Often times we'll say something like "I know that I'll get a raise at work" or "I'll know that the cowboys will win tomorrow" but do we really?

Here's an intereting case. Let's say you want to know the time. You look at your watch, and the watch reads 3:15. In reality, it really is 3:15. But... the watch is broken. It's been stuck on 3:15 for days, you just don't know. Can we say that you knew it was 3:15. Sure the watch said 3:15 so you believed it to be 3:15 and it was 3:15, but the watch wa broken. I think most people would contend that you didn't know the time.

The clock case is a good example of the traditional view of justified true belief (jtb). It goes like this
For S to know P
1. S must believe P (It makes no sense to say: "I know it's raining but I don't believe it"

2. P must be true (I think no further explanation is needed here)

3. S must be justified in believe P (Otherwise the clock case would be knowledge, or any wild belief that we have that HAPPENS to be true would also be knowledge)

There are many problems with jtb that many philosphers have shown and tried to solve. I personsally think that justification is a vague term. Many philosophers believe that a 4th requierment is needed. What do you SMP'ers think?

If anyone likes, I can further discuss some problems and solutions some philosophers have presented regarding jtb.