Intermediate and high energy heavy ion collisions provide a unique opportunity to investigate the properties of hadrons in dense nuclear matter.In particular, strange mesons are considered to be sensitive to in-medium modifications.Theory predicts a repulsive K+N potential and an attractive KN potential in dense matter [1].A repulsive K+N potential would repel the K+mesons from the bulk of the nucleons and therefore cause an preferred out-of-plane emission of K+ mesons at midrapidity and a directed flow opposite to the nucleons at target and projectile rapidity.