message
Entity: predicate

Usage:
message(Title, Text, Icon)

Invokes an application modal dialog box with a single OK button.
 
Title  the title of the dialog box window
Text  the text inside the window (usually some information to be displayed)
Icon one of the predefined message icons

Example:

?-
  message("Message(..) test", "Sample Message", !),
  write("OK"), nl.

See also:

 yes_no