ZAGREB, Jan 21 (Hina) - Croatian President-elect Ivo Josipovic told Tanjug the trend in Croatia-Serbia relations was "absolutely positive", claiming minor ups and downs were not the most important and that the two countries' politicians should build a climate of trust and optimism. He said the biggest obstacle to the withdrawal of Croatia's genocide claim against Serbia was the fact that Ratko Mladic and Goran Hadzic were still at large.