如何使用TwoWay绑定回滚对silverlight 3中的对象所做的更改

I have a Silverlight 3 project. I have a textbox that is TwoWay data bound to an object. If the user wants to cancel the changes that they made to the textbox, what is the best way to undo the changes to the bound field on the object?I have a Silverlight 3 project. I have a textbo