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 seconds
| ON TIMER 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
| 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 CHARclause 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 
F11orControl-z). - action-name identifies an action that can be executed by the user.
 - 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  
CENTURYattribute. - format-spec is a string defining the display
format for the prompt field,  like the 
FORMATattribute. - picture-spec is a string defining the input format for the prompt field, like
the 
PICTUREattribute.