Reference_Syntax.accessKey = “character
The value of this attribute is a single character. When the user synchronously presses the platform-specific modifier key and the single character, the form’s focus shifts to this field. On Windows systems, the modifier key is the ALT key and on Mac OS systems, it is the OPTION key.
For example, if the form author sets the accessKey of a field to f and a Windows user presses Alt+f, the focus shifts to that field.
Form Model

accessKey