The little amber light located on your dashboard is a warning light. It says, "Check Engine," and upon seeing it, most people panic, or totally ignore it. Both of these attitudes are slightly extreme under the circumstances. What it actually does is warn you that there is a problem. It's a warning light, not a disaster light. But, if you ignore it, you're asking for a disaster down the road. The first thing you should do is check your gas cap, for this is frequently the problem. If your gas cap is not screwed on all the way, the light will come on, as your gas emission system detects that.
Don't panic, but do make an appointment or go to a service technician immediately. The light is an indicator that something needs to be adjusted and checked. Simply take the car to an authorized technician, and he can use a portable diagnostic computer that plugs into your car's computer system right under your dash board. He can tell in minutes what the problem is, and take steps to rectify it. See your dealer for these diagnostics.