In the old days，the lines between work and leisure time were markedly clearer. People left their offices at a predictable time，were often completely disconnected from their jobs as they traveled to and from work，and were offduty once they were home.That’s no longer true.In today’s highly competitive job market, employers demand increased productivity,expecting employees to put in longer hours and to keep in touch almost constantly via fax，cell phones，email，or other communications devices.As a result，employees feel the need to check what’s going on at the office，even on days off.They feel pressured to work after office hours just to catch up on everything they have to do.They work harder and longer, change their work tasks more frequently,and they worry more about job security.