2004 Alero security light flashing & engine will not turn over

My girl has a 20004 Alero and she has the security problem at least one time almost everyday. When she tries to crank it, the sec light will be flashing. She turns the key to the on position for 10 mins. The light becomes solid. Then she can crank it.I have seen a video on YouTube of someone putting a toggle switch on the security wire on a Grand Am. Can I put this toggle bypass on her vehicle or is there a better fix? Someone with knowledge of this particular make and model please help me. I am not a mechanic but I do have a lot of common sense and if you tell me what needs to be done, I can probably handle it myself without paying $99 just for the dealership to diagnose the problem. Then I will have to pay more for the fix. Too much money!!! Any help will be greatly appreciated!!!

If she has a 2nd key, try that one.

http://www.bergerweb.net/AleroSecurity/

That is a permanent fix. That being said, I had the same problem and instead of doing that, I tried a never before used spare key. The light stayed off and hasn't been back on since. A worn key will definitely trip the sensor.