Ford Repair: check engine light, mercury mountaineer, gas cap

Question
Hello;

    I have a 1998 mercury mountaineer.  The check engine light came on yesterday.  Someone told me that it could be something as simple as the gas cap being loose.  Lo and behold the gas cap was almost off.  I put the gas cap back on.  The check engine light did not go off.  Is there a reset switch or could it be something else that could be triggering this light to come on.  The car does not drive any differently.  Do you have any suggestions of other things that I could check?

Answer
John-

  It was probably just the cap.  Problem is once the code is there it needs to be reset or cleared.  Usually the "homemade" trick will work.  Unhook the battery and then place your key in the ignition and turn it to the "accessory on" position.  Leave it for about 10-15 minutes and then remove the key and hook the battery back up.  Sure, you'll have to reset your clock and radio presets...but if it works it's a free alternative to having a shop clear the code for you.  Hope this helps.

Steve