Employees who regularly use company computers to surf the Web, sign on to business accounts for personal e-mail, make calls from company phones or use the corporate car to run errands run the risk of losing their jobs, according to a new survey released by The ePolicy Institute and the American Management Association. More than 58 percent of the 304 companies surveyed said they’d fired workers for misusing company-provided e-mail accounts or improper use of the Internet on a company computer.