Do i have to validate the column name by code?

not to accept empty values or duplicate name?

i have a problem with the collection class, that class have a method name "OnSetComplete", that it is supposed to fire when the value of the class change, but it does not work.

i have MSFlexGrid at wich i add Column Collection property, so at design time when i add objects and change the values on the collection property window, it does not fire "OnSetComplete", but OnInsertComplete works, why?