Browse:AddBlock(LongName,ShortName,VarName,Block,DoGet,Picture,When,Valid):
  public: return true
  Next column of the table is appended to this object.
  During the editation is the record virtuality not tested i.e. database
  record can be edited even if RecNo()>LastRec().

  Parameter description
  ~~~~~~~~~~~~~~~~~~~~~
  LongName: character: default is ShortName
   It is name of column used in Form mode.

  ShortName: character: default is ""
   It is name of column used in Browse mode.

  VarName: character: default is ShortName
   It is name of edited variable, or the name of database field and will
   be saved as information to clipper Get objet created in this method
   and saved to array DoGet. It is because clipper get object used for
   editation should know the name of the edited variable.

  Block: code_block: no default
   It is code block of get/set type, you can create by clipper functions
   FieldBlock(), FieldWBlock(), MemVarBlock() or by own piece of program.

  DoGet: code_block: default is virtual_method_Browse:DoGet()
   It is code block which with help of Get object edits a variable
   (database field) in current table column.

  Picture: character: default is ""
   It is display mask for display mode of current column.

  When: code_block: default is {||true}
   It is code block, evaluated before entering the editation of current column,
   if it is false the editation is skipped. Could be used for computed fields
   of table or read-only columns.

  Valid: code_block: default is {||true}
   It is code block, evaluated after finishing of editation of current
   column. His job is to evaluate if the new entered value is valid,
   in this case returns true, otherwise false.