Triggers a script to run when an object is active and receives one or more characters from the keyboard, either directly or via an input method editor (IME). Use the Get(TriggerKeystroke) function to return the characters that activated the script trigger.
When the script runs
Before the event has been processed.
Modes in which the trigger can be used
Browse and Find modes.
You can use the Exit Script script step within the triggered script to return True or False.
Originated in 
FileMaker Pro 10.0
Use the Get(TriggerModifierKeys), Code, and Char functions to work with special characters such as navigational keys like the Tab and the arrow keys, and with general Unicode characters. See the Code function for a list of navigational keys and the codes reported to a script. The Char function returns the characters for Unicode code points.
A script triggered by OnLayoutKeystroke processes the characters.
The first of these steps to use the key stops the process. A script executed by the OnObjectKeystroke or OnLayoutKeystroke script trigger can stop further processing of the keystroke by returning False.
The OnObjectEnter, OnObjectExit, and OnObjectKeystroke script triggers can be activated when assigned to summary and calculation fields.
See Changing object data without activating script triggers for a list of actions that do not activate this trigger.
Related topics 
Setting up script triggers
Setting script triggers for layouts
Setting script triggers for objects