<p>January 27, 2003 -- New Jersey Sen. Frank Lautenberg underwent surgery yesterday to treat a head injury from a skiing accident in Aspen, Colo., a month ago.</p>
<p>The Democratic pol, who turned 79 on Thursday, fell and hit his head while skiing on Ajax Mountain in late December, said Tim Yehl, a spokesman for the senator. He had had a low-grade headache since then.</p>