In Squeak 4.1, there is no method #closeInWorld. If you want to "close" a Workspace (or any other Morph in the world), send it #delete. HTH, Sean -- View this message in context: http://forum.world.st/how-Can-I-regiter-In-squeaksource-tp3176931p3179241.html Sent from the Squeak - Beginners mailing list archive at Nabble.com.