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:
1st Period— 8th Grade Girls Athletics
2nd Period— 7th Grade Girls Athletics
3rd Period— 6th Grade P.E.
4th Period— 8th Grade U.S. History
5th Period— Advisory
6th Period— Conference
7th Period— 8th Grade U.S. History
8th Period— Conference