Hi, All; Suppose I have a class 'dat' such that setClass('dat', representation (.version='character', x='numeric', y='numeric')). If I want to make a method that changes the .version slot of 'dat' class in a way like set.version(d) <- '0.2' when d is an object of 'dat' class, how can I do this? Thanks in advance. Tae-Hoon Chung Post-Doctoral Researcher Computational Biology Division, TGEN 445 N 5th St. Phoenix, AZ 85004 USA O: 1-602-343-8724 F: 1-602-343-8840 [[alternative HTML version deleted]]