When I define a message smalltalkDoc in the class "Class" it does not have problems there. But when I try to define a subclass "SmalltalkDoc" of "Class" and put the message smalltalkDoc in this class, by evaluating for example the expression "LinkedList smalltalkDoc." I have a message context : "LinkedList class(Object)>>doesNotUnderstand: #smalltalkDoc." How can I fix this? here the message. smalltalkDoc    "Genere un fichier HTML avec les Informations d'une classe" |stream nom| nom:=self asString,'SmalltalkDoc.html'. stream := FileStream forceNewFileNamed: nom. stream nextPutAll: '<html> <head> <title>A little Smalltalk Doc</title> </head> <body> '; nextPutAll: '</p>'; nextPutAll: 'class name : '; nextPutAll: self name asString; nextPutAll: '</p>'; nextPutAll: '<p></p>'; nextPutAll: 'superclass name : '; nextPutAll: self superclass name asString; nextPutAll: '<p></p>'; nextPutAll: '<p></p>'; nextPutAll: 'trait Composition : '; nextPutAll: self traitCompositionString asString; nextPutAll: '<p></p>'; nextPutAll: '<p></p>'; nextPutAll: 'class trait Composition : '; nextPutAll: self class traitCompositionString asString; nextPutAll: '</p>'; nextPutAll: '<p>'; nextPutAll: 'category : ' ; nextPutAll: self category asString; nextPutAll: '</p>'; nextPutAll: '<p>'; nextPutAll: 'instances Variable Names : '; nextPutAll: self instVarNames asString; nextPutAll: '</p>'; nextPutAll: '<p>'; nextPutAll: 'pool Dictionary Names : '; nextPutAll: self poolDictionaryNames asString; nextPutAll: '</p>'; nextPutAll: '<p>'; nextPutAll: 'class instances Variable Names : '; nextPutAll: self class instVarNames asString; nextPutAll: '</p>'; nextPutAll: '<p>'; nextPutAll: 'type of class : '; nextPutAll: self typeOfClass asString; nextPutAll: '</p>'; nextPutAll: '<p>'; nextPutAll: 'class Comment : '; nextPutAll: self organization classComment asString asString; nextPutAll: '</p>'; nextPutAll: '<p>'; nextPutAll: 'comment Stamp : '   ; nextPutAll: self organization commentStamp asString; nextPutAll: '</p>'; nextPutAll: '<p>'; nextPutAll: 'class Variables Names : '; nextPutAll: self classVarNames asString ; nextPutAll: '<p>'; nextPutAll: 'selectors : '; nextPutAll: self class selectors asString ; nextPutAll: '</p>'; nextPutAll: '</p>'; nextPutAll: '</body> </html>'. stream close.  ------------------------------------ Hayatou Â