All athletes who are planning to compete at the major USA Wrestling events scheduled for Las Vegas, Nev. next week must pre-register for the event right away.    The events that have MANDATORY pre-registration are the 2005 United States National Wrestling Championships, the Men's FILA Junior National Championships and the Western Junior Regional Championships. These events will be held at the Las Vegas Convention Center in Las Vegas, Nev., April 27-30.    All athletes in all divisions MUST pre-register online or by mail before Tuesday, April 26 at 12:00 noon Pacific time.     THERE WILL BE NO ON-SITE REGISTRATION OR LATE REGISTRATION. THERE ARE NO EXCEPTIONS TO THESE PROCEDURES.    To pre-register, visit the following website:   http://www.lvsports.org/events/wrestling.entry_form.main.html    Consent and waiver forms must be copied, completed and brought to check-in before weigh-ins at all of the events. Athletes can print a consent and waiver form from the website in advance, as part of the pre-registration process.    In addition to pre-registering the athletes online, there is also a process for coaches to pre-register their team rosters on the web page.    Athletes who are representing a specific club during the championships must be registered on-line as part of that club. Athletes should make sure that their wrestling club has placed them on the official roster by the April 26 deadline.    The U.S. National Wrestling Championships is the annual national tournament in all three styles of international wrestling: men's freestyle, men's Greco-Roman and women's freestyle. The nation's best wrestlers compete for national titles and All-American honors at this outstanding showcase event.    The Men's FILA Junior National Championships feature the nation's most talented athletes who are 17-20 years old, and includes both freestyle and Greco-Roman.     The Western Junior Regionals features the top high school wrestlers in the region and the nation, competing in freestyle and Greco-Roman. This is annually the largest of the Junior Regional events and features a very strong field of competitors.    For more information, visit www.LVSPORTS.org, or contact  Event Director Larry Barnson of the Las Vegas Sports Committee at 1820 Cypress Greens Ave, Henderson, NV 89012. Barnson can be reached via E-mail at lvoc@aol.com.