This sample shows how to use the dialog API to customize dialogs whithout
changing the original editor code. The following customizations are being
done::
Add dialog pages ("My Tab" in the Link dialog).
Remove a dialog tab ("Target" tab from the Link
dialog).
Add dialog fields ("My Custom Field" into the Link
dialog).
Remove dialog fields ("Link Type" and "Browser Server"
the Link dialog).
Set default values for dialog fields (for the "URL"
field in the Link dialog).