In a new procedure, there will be a pre-seeding process conducted for the U.S. National Championships in all three Olympic wrestling styles, which will be contested in Las Vegas, Nev., April 29-30.    A pre-seeding committee has been established in each style, which will evaluate the wrestlers who have pre-registered to compete. The pre-seeding will be published for each weight class in men's freestyle, men's Greco-Roman and women's freestyle.    The pre-seed committee structure has been approved by the Sports Committee in each style. Included on the pre-seed committees are representatives of the three top-scoring wrestling clubs from last year's U.S. Nationals, as well as the USA Wrestling National Coach in each style, plus an additional committee member approved by the President of USA Wrestling.    The pre-seeding committee will seed eight athletes in each weight class, which will then be published on TheMat.com and provided to the wrestling media.    At the U.S. Nationals, a seeding meeting will be held, with representatives of the club programs included. There will be an opportunity to adjust the pre-seeds at that time, with a two-thirds vote required for change. If there is a desire to have more than eight seeds at any weight class, the additional seeds may be added on a majority vote of the club representatives.    All athletes in all divisions must pre-register on-line or by mail before Tuesday, April 26. No athlete may be added to the competition after this deadline date.    For information, as well as to pre-register for the tournament, visit the U.S. Nationals website at:  http://www.lvsports.org/current_events.html