{ HLOUSEK.PAS                           Copyright (c) Lukas Hlousek }
{ Unit pre program na simulaci pokladny.                            }
{                                                                   }
{ Datum:10.01.2007                             http://www.trsek.com }

unit Hlousek;

interface
function VyberVolbu(Text:string; Nabidka:string):char;

implementation
uses crt;

function VyberVolbu(Text:string; Nabidka:string):char;
var
  vybrano: char;
  pozice:  byte;
begin
  Write(Text+' ');
  repeat
    vybrano:=UpCase(ReadKey);
    pozice:=Pos(vybrano,nabidka);
    if pozice=0 then
    begin
      Sound(500);
      Delay(20000);
      NoSound;
    end;
  until pozice<>0;
  VyberVolbu:=vybrano;
end;

{ Vstup z klavesnice s omezenim poctu znaku }

uses Crt;

const
  CR=#13;
  BS=#8;
  Num=['0','1','2','3','4','5','6','7','8','9'];

var
  InpBuf: string;
  InpChr: char;
  MaxLen: byte;

begin
  MaxLen:=8;
  ClrScr;
  InpChr:=#0;
  InpBuf:='';
  while InpChr<>#13 do
  begin
    InpChr:=ReadKey;
    case InpChr of
      BS: Delete(InpBuf,Length(InpBuf),1);
    else
      if (Length(InpBuf)<MaxLen) AND (InpChr in Num)
        then InpBuf:=InpBuf+InpChr;
    end;
    GotoXY(1,1);
    ClrEol;
    Write(InpBuf);
  end;
end.

begin
end.