Opening a Pointing Device

The open statement activates a mouse or touchscreen as a pointing device. (If one of these devices is your system's default device, it is already activated.)

Usually, open is part of a response to start response definition. For example:

response to start 

 open touchscreen

Closing a Pointing Device

The close statement closes a pointing device that was open. Once a device is closed, the pointer disappears from the screen, and you can no longer use the device for selecting enabled graphical objects. For example:

response to ...
 close mouse

If an alternate device is still open when ESL encounters an exit statement, the device is implicitly closed. If the device is open when ESL encounters a change to program statement, the device remains open for the new ESL program.