Hi, I am new to PL/SQL, I'm trying to execute the commands that I learned at the course. VARIABLE area NUMBER DECLARE radius NUMBER(2) := &s_radius; pi CONSTANT NUMBER := 3.14; BEGIN :area := pi * radius * radius; END; I understand that I can run this using SqlPlus, but I remember my teacher was running this from the web browser using Application Express. I try to run the same commands there, at HOME SQLSQL Commands, but I keep getting the error "ORA-00900: invalid SQL statement" . Can you help me run it in Application Express or point me to a way where I can use an editor to run these course exercises? Thanks!