%N promptf %F $MIR/src/subs/promptf.for
%D Prompt for real value from standard input.
%: terminal-i/o
%P mchw
%B
        subroutine promptf(value,format,prmpt,default)
        implicit none
        character*(*) format,prmpt
        real value,default

  Prompt for real value from standard input (usually user terminal)
  in format 'prmpt' (default) :
  <cr> returns value=default

  Input:
    format     Format string for default and value. e.g. f10.3
    prmpt      Prompt string.
    default    Default value.
  Output:
    value      Value read from standard input.
