A 25-year-old Madison man has been missing for five weeks after parting with his mother in Vienna. They had been vacationing together. Susan Stone left for the U-S June 22nd and Jonathan Luskin was planning to travel to Slovenia. Luskin had planned to hike in a Slovenian national park, making stops in Croatia and Greece before returning to his home in Hong Kong. He didn’t make any of those stops. Luskin’s roommate called the family to say he hadn’t heard from the missing man either.