After taking heavy losses as stocksdove, many 401(k) participants arepulling out of plans. Enrollment in401(k) plans is at 72%, according toa survey by human resources consultantsBuck Assoc, down from 77% in1999. According to retirement experts,that's a big mistake, even ifyour 401(k) account has been mangledby the market's swoon. It's especiallynot smart if the employermatches all or part of what you putinto the account. If you're skittishabout stocks, most 401(k) plans offera less risky alternative, like a bondfund or a money market fund, whereyou can park your investment untilthe stock market perks up again.About 50% of US physicians participatein 401(k) plans.