>When we do a new propertie and _Assign clause VFP show us two new peoperties, "XXXXX" and "XXXXX_Assign", in the _Assign clause we have a subroutine and in XXXXX propertie .F.

Carlos,

There is actually only one new property and that is XXXX the XXXX_assign is an assign method. The assign method is like an event in that it fires any time anything tries to assign a value to the property. Initially the assign method has only three lines of code in it;

LPARAMETERS vNewVal
*To do: Modify this routine for the Assign method
THIS.xxx = m.vNewVal

vNewVal is the value that is begin assigned to the property, This.xxx = vNewVal is the line of code that actually does the assignment. If you want to capture the act of assigning a value to the property you can wriute your code in the xxxx_assign method.

A corelary to the assign method is the access method. It is named XXXX_access and it fires whenever anything tries to read the property's value.