LET /PROMPT

###
LET /PROMPT

            [SIC\]LET Variable [=] [Expression] /PROMPT "Explanatory text"
                    (GUI input mode and Command line mode)

        Create  a  text  widget,  with  a specified prompt, to return a value or
        valid expression for the variable. The text  widget  can  be  pre-loaded
        with  an  expression  or value(s). Standard input will be available once
        the widget is created by command GUI\GO.