(MONEY Magazine) – Your manager asks you to shred some inflammatory documents. Or keep bad news from a client. Or back her up in a lie. Whether the task is illegal or simply immoral, the dilemma is a common one: Nearly half of American workers say they've had to choose between doing what they felt was right and what their supervisor ordered, according to a survey by ethics consulting firm LRN. These steps can help you emerge from the quandary spotless, but not jobless.

• Get the facts. Almost 10% of the employees who felt they were asked to do something unethical eventually determined that their boss' request was appropriate. Before you claim the moral high ground, ask your boss for more info about what you're being asked to do and why. Or discuss the situation with a trustworthy and wise colleague, who may be able to reassure you that the task is legitimate.

• Offer alternatives. If your concern turns out to be justified, try proposing another, aboveboard way to reach the same objective. "It's the easiest and best exit out of the problem," says David Batstone, a professor of ethics at the University of San Francisco. Chances are, your manager just wants the goal met and may not care how.

• Be frank, tactfully. No easy out? Try candor, framed diplomatically. "Talk to your boss about why the task makes you uncomfortable and why you think it's not in the company's best interests," says Alice Darnell Lattal, co-author of Ethics at Work. "He may understand your perspective and end up rescinding the request."

• Take it to a higher power. If all else fails, and you're still feeling distressed about carrying out orders, speak confidentially to your manager's boss or an HR rep. This is an imperative if completing the assignment would force you to violate a law. "My boss made me do it" might ease a guilty conscience, but it doesn't usually hold up in court.