You can use dialog boxes to respond to user input.
With AutoCAD®, you can design and implement dialog boxes to use with your applications. The appearance of a dialog box is defined by dialog control language (DCL) files, as described in Designing Dialog Boxes. You control the functionality of a dialog box with an AutoLISP® application. This chapter describes how to control dialog boxes using AutoLISP. Although this chapter shows some examples of DCL files, you may find it helpful to read Designing Dialog Boxes before reading this chapter.