How to redefine a constructor from parent class

[marcoE]

Hello guys.
Firstly I don't really know if this is possible.

This is my Class Diagram:
https://dl.dropboxusercontent.com/u/710615/class%20diagramV4.png

github:
https://github.com/CreativeSoftware/DiamondQTv3

I want to redefine the price object of the Book Class.
However price is defined at Products Class.

I want the price value change according to the marker value, which is a Book attribute.
If the marker is blue, price gets a value of 10 (e.g.), if it has another value, price is equal to 20.

[iQChange]

Hoah, take a look at the virtual keyword.