How to react
If you are fired for reasons beyond your control such as mergers or takeovers, you can ask for a letter of recommendation. It will help your confidence and that of your prospective employer.
If your company has a severance package, and you are eligible, negotiate. Don't accept the first offer. Explain to them that your finances are going to be directly affected by the unexpected loss of your job and that you need a better package.
Do not shout or insult your boss or company. You need all the goodwill you can get. Prospective employers will be calling the very people you are cursing for references.
Remember, both getting fired and firing someone are unpleasant situations.
Kavita Singh, an HR professional for the past five years, says, "Firing someone is the most unpleasant part of my job. I have had people bursting into tears, refusing to accept they are fired or even yelling loudly. It just makes a difficult situation more embarrassing."