I don't know what the problem is, but a temp fix would be to hook your laptop up to a tv as an external monitor. Annoying, but it'll do the job while you try to figure out what's wrong and what your options are.

Again just so you know right now I am replying with the same laptop I am talking about.

So how do I tell the difference looking on an external moniter?

You don't. Like I said, I have no idea about it. I'm just saying using an external monitor will allow you to use your laptop (hopefully) without the screen going out, thereby allowing you to look for the issue and fix without having to worry about what happens if the screen going out entirely.

I've had a similar problem with my laptop, but only while running on battery. In my case, if I were to, e.g., play a youtube video, the entire screen would sometimes wash out in a single hue, possibly related to the colours in the video. The machine remained responsive, though, so I could pause using the spacebar. Some other heavier applications could also cause this, but I generally avoided running heavy stuff while on battery. The problem could be fixed by putting the notebook in standby, cutting power to the monitor and other parts, then waking it back up. This never happened when the AC cord was plugged in. I never managed to figure out just what caused this effect, though I learned to anticipate it and cope with it, and it seemed fairly benign.

The point of all this is, it may be a power issue/old battery/something unknowable :P You're not very computer savvy, so manually cutting power to some unused parts might be a bit too involved for you, but just trying to diagnose contributing factors, like whether it's running on battery or off the grid, could help you out.

Sounds like the backlight is on its way out.

Sounds like the backlight or the connection is broken, which if it is than you're lucky that is a cheap fix. If it does break simply plug in a monitor or tv and it will do the job nicely.

The external monitor may help determine if it's the screen or the video card. No difference for most people, as both faults usually require or it's just cheaper to purchase a new computer.

Have you had any lighting issues or lines appearing on the screen ?
Are you having this issue everytime ? Is it always black now ?
Or does it only happen when playing a game / running a certain program ?
If so, it might be caused by a video driver crash.

I am replying to you in the laptop I am talking about.

1.No on both

2. It stared on Last Tuesday at around 2:00 and so far it happened 3 times, but when I turned it back on the screen comes back.

3. Well the last 2 times I was playing Baldur's Gate 1 when it happen, but the first time it did happen, my mother was using it for studying for a test, it was music stuff I heard music coming out of the laptop,

And you didn't get a blue screen ? Just the screen being black while the rest was still going, right ?
I'm guessing it's either the video card driver that isn't responding or a problem with the screen/connection from the screen to the mainboard.
As some have adviced already, try using it with a tv or an external computer screen and see if it does it again. If it doesn't, it's probably a problem with the screen itself.

No blue screen, and when I meant black I meant as if the computer screen is off/shut down, not that the screen is on but shows black.