The application simulates the presence of a column with the name of an image file.
This has been done only because the Northwind database does not come with a reliable column
with this characteristic. You should adapt the content of the PhotoPath column in order 
to do this. For this reason, I assume that the image to display has a BMP extension and a
filename that is the last name of the corresponding employee. In addition, all images are 
expected to stay in an "images" subfolder. 

This does not correspond to a real-world scenario. However, in a real-world scenario, 
you normally have just one column to read and write and things are significantly easier 
than in this code. How things normally go in realistic scenarios is described in the book.