Syntax of PROMPT instruction

The PROMPT statement assigns a user-supplied value to a variable.

Syntax

PROMPT question
    [ ATTRIBUTES ( display-attribute [,...] ) ]
    FOR [CHAR[ACTER]] variable
    [ HELP number ]
    [ ATTRIBUTES ( control-attribute [,...] ) ]
[ dialog-control-block
   [...]
   END PROMPT ]

where dialog-control-block is one of:

{ ON IDLE idle-seconds
| ON ACTION action-name
| ON KEY ( key-name [,...] )
}  
    statement
    [...]

where display-attribute is:

{ BLACK | BLUE | CYAN | GREEN
| MAGENTA | RED | WHITE | YELLOW
| BOLD | DIM | INVISIBLE | NORMAL
| REVERSE | BLINK | UNDERLINE
}

where control-attribute is:

{ ACCEPT [ = boolean ]
| CANCEL [ = boolean ]
| CENTURY = "century-spec"
| FORMAT = "format-spec"
| PICTURE = "picture-spec"
| SHIFT = { "up" | "down" }
| HELP = help-number
| COUNT = row-count
| UNBUFFERED [ = boolean ]
| WITHOUT DEFAULTS [ = boolean ]
}

question is a string expression displayed as a message for the input of the value.
variable is the name of the variable that receives the data typed by the user.
The FOR CHAR clause exits the prompt statement when the first character has been typed.
number is the help message number to be displayed when the user presses the help key.
key-name is an hot-key identifier (such as F11 or Control-z).
action-name identifies an action that can be executed by the user.
idle-seconds is an integer literal or variable that defines a number of seconds.
statement is an instruction that is executed when the user presses the key defined by key-name.
century-spec is a string specifying the century input rule, like the CENTURY attribute.
format-spec is a string defining the display format for the prompt field, like the FORMAT attribute.
picture-spec is a string defining the input format for the prompt field, like the PICTURE attribute.