SOMERSET COUNTY - Zach Horton, a fifth-grader at St. Elizabeth School in Bernardsville, said he wants to be a writer when he grows up. His first published work was revealed yesterday -- the cover of the Somerset County Prosecutor's Office 2005 Anti-Drug Calendar. Horton was one of 12 fifth- and sixth-grade students who were recognized for their posters, featured in each calendar month, at a brief ceremony at the Somerset County Prosecutor's Office. The students were asked to draw posters reflecting anti-substance abuse and anti-violence messages and reinforce what they learned in the Drug Abuse Resistance Education program, commonly known as DARE. [continues 328 words]