An autopsy shows inconclusive results after a Dunlap High School student mysteriously died.  Now, officials are depending on toxicology reports to help determine what happened to 16-year-old Joshua Olt.   A friend found him unresponsive in his bedroom on Sunday evening.  Olt was rushed to the hospital where he died about two hours later.  The teen's parents were vacationing in Mexico at the time of the death.  Grief counselors are on hand at Dunlap High School to help students deal with the tragedy.