[Gretl-users] Dummy

Dear Gretl users, I am aware that the following might be trivial, but I am stuck. Suppose that you have a panel data set whose units are countries identified by a numerical variable, say "ccode". And you want to split the sample into two sub-samples: OECD and non-OECD members. I have tried the following: genr OECD = 0 if ccode == 1 replace OECD = 1 elif ccode == 4 replace OECD = 1 (...) end It does not work. I am aware of the piece of warning in the Hansl's manual for Stata users (page 32). But, does anyone know hos I should do this? Thanks a lot in advance for your cooperation. Cruz