Dell Inspiron 6000 screen problem, please help!

My screen on my dell laptop has recently gone dark in the middle of operation. It doesn't shut off completely because if you look really closely you can see it's still on. If i reboot, the screen comes back on at startup, a little darker than usual but gradually gets lighter, and then after about 10 seconds it goes dark again. The same thing happens after standby. It comes back on for a few seconds, then goes off. The time that it stays on has been getting shorter and shorter. The rest of the computer seems to run fine. Any ideas of what the problem is, or what to do???

Please help!