Alternative way of using too many else if's when using if?

[Arjang Assadi]

I need to do something similar to do this :

if (e.Value  is Book)
        {
            e.Value = (e.Value as X).Title;

        }
        else if (e.Value is Customer)
        {
            e.Value = (e.Value as Customer).FullName;
        }
        else
        {
            e.Value = "Unknown";
        }
etc.

in DataGridView_CellFormatting even, but it just looks plain ugly. is
there way to do this in a more structured manner?

Regards

Arjang