modifiedField - previous value

Source: http://efreedom.com/Question/1-209764/Get-Previous-Field-Value-ModifiedField-Method-Dynamic-Ax-Table

Q: I would like to be able to perform some logic in the table.modifiedField method which compares the previous value of a field to the new value. How do I get to the previous value?

A: The record buffer as it was before any modifications is available through the this.orig() method.

Example:
public void modifiedField(fieldId _fieldId)

{
    super(_fieldId);
    info(strfmt("Field number %1 changed from %2 to %3",_fieldId,this.orig().(_fieldId),this.(_fieldId)));
}