For Mac OS users, there is a system setting that may not allow you to tab onto several types of elements in a web page. To change this setting:
Sitting: Thelma Hartley, Dr. J.W. Blattner (Superintendent), and Mildred Hampton.
Standing: Fred Adkins, Edmund Casebolt, Tom Lee, Mrs. J.W. Blattner, Edna Fisher, Charles Hillier,
and Stanley McElhaney.