>> << Ndx Usr Pri Phr Dic Rel Voc !: wd Help User

# Window Driver Overview

The J/Windows interface is referred to as the Window Driver and provides access under program control to many features of the Windows graphical and operating system environment. It provides essentially two mechanisms for communication:

- you can send instructions and queries to Windows.
- you can react to events signaled by Windows, such as the press of a button on a form.

  The verbs `wd` and `wdhandler` defined in script file `winlib.ijs` provide these mechanisms:

- `wd` is used to send instructions and queries to the Window Driver - and is the only way of doing so.
- `wdhandler` is used to react to events signaled by Windows. It is the standard way of doing so, but may be changed if required.

  These verbs are defined in the standard profile when you load J.

>> << Ndx Usr Pri Phr Dic Rel Voc !: wd Help User