This short article offers good career tips for older workers (that's everyone over 40) who want to keep their jobs.
I would add that, regardless of the industry you're in, be proactive about getting training in current technology and software, even if it is above and beyond what is directly required for your position.
We help many older workers who have lost their jobs, and I can tell you from their experience that you do not want to be in that position. It's a difficult time of life to be wondering where the next mortgage, tax and tuition payments will come from. And even if you have been the victim of age discrimination, getting financial redress will take time, quite possibly years. So the old adage that “an ounce of prevention is worth a pound of cure” certainly applies here. Do all that you can to keep yourself relevant in your workplace.