Using Field-Level Context-Sensitive Help
You can take context-sensitivity one step further and implement field-level help (sometimes called What’s This? help). In this scheme, the user clicks a button or selects a menu item that causes the mouse pointer to change—perhaps to a question mark. The user then clicks a control, such as a button or selection box, and the application displays online help specific to that control.
The TypeFacer application consists of buttons, boxes, and text-display areas, all of which are potential targets for field-level help. For example, a user might not know what the Show button does—a situation perfect for using field-level help. Figure 7.7 shows the help system after a user accesses field-level help for the Show button.

Figure 7-7. Field-level help
Programming Field-Level Context-Sensitive Help
Field-level
context-sensitive help works like screen-level context-sensitive
help. You use the same setHelpIDString( ) method
as for screen-level help. Using this method, you provide a map ID for
every component in the application, not just its usage modes or
screens.
Use the following steps to add field-level context-sensitive help to
the TypeFacer application. For this revision of the program, all the
lines to be uncommented start with //#4.
Associate a help topic with each user-interface component:
// assign map IDs for field-level context-sensitive help CSH.setHelpIDString(inputField, ...