имеется база данных электродвигателей. необходимо обеспечить возможность удаления из базы информации о конкретном типе двигателя

program zad_29_31;
uses crt;
type owner=record
  tip:string[30];
  Unom:integer;
  Pnom:real;
  Wnom:integer;
  Mnom:real;
  KPD:real;
  end;
var karta:owner;
f:file of owner;
fname:string;
  tip_:string;
  Unom_:integer;
  Pnom_:real;
  Wnom_:integer;
  Mnom_:real;
  KPD_:real;
ch:char;

procedure enter(fname:string);
var
ch1:char;
begin

  assign(f,fname);
     rewrite(f);


  while ch1<>'n' do begin
    ClrSCr;
    seek(f,FileSize(f));
    write('tip dvigatelya: ');
    readln(karta.tip);
    write('nominalnoe napryajenie: ');
    readln(karta.Unom);
    write('nominalnaya moschnost: ');
    readln(karta.Pnom);
    write('nominalnoe chastota vraschenia: ');
    readln(karta.Wnom);
    write('nominalnyi moment vraschenia: ');
    readln(karta.Mnom);
    write('KPD: ');
    readln(karta.KPD);
    write(f,karta);

    writeln('dannye vneseny v fail');
    write('povtorit vvod? (y/n)');
    readln(ch1);
  end;
  writeln('dlya vozvrata v glavnoe menu - Enter');
  readln;
  close(f);
end;

procedure dop;
var ch1:char;
begin
assign(f,fname);
reset(f);
seek(f,filesize(f));
writeln('**************************************');
writeln('novye dannye');
writeln('**************************************');
    write('tip dvigatelya: ');
    readln(karta.tip);
    write('nominalnoe napryajenie: ');
    readln(karta.Unom);
    write('nominalnaya moschnost: ');
    readln(karta.Pnom);
    write('nominalnoe chastota vraschenia: ');
    readln(karta.Wnom);
    write('nominalnyi moment vraschenia: ');
    readln(karta.Mnom);
    write('KPD: ');
    readln(karta.KPD);
    write(f,karta);
    writeln('dannye vneseny v fail');
    write('povtorit vvod? (y/n)');
    readln(ch1);

  writeln('dlya vozvrata v glavnoe menu - Enter');
  readln;
 close(f);
 end;

procedure del(fname:string; tip_:string);
var






BEGIN
repeat
  ClrSCr;
  writeln('1.sozdat fail');
  writeln('2.dobavit dannye');
  writeln('3.ydalit dannye');
  writeln('4.prosmotr dannih');
  writeln('5.exit');

  ch:=readkey;
  case ch of
     #49: begin
        ClrSCr;
        write('pyt i imya faila: ');
        readln(fname);
        enter(fname);
      end;
     #50: begin
     write('pyt i imya faila: ');
     readln(fname);
     dop;
       end;
    #51:begin
      write('pyt i imya faila: ');
     readln(fname);
     del;
      end;
    #52:begin

        end; }

  end;
  until ch=#53;
  exit;
END.

А в чем конкретно вопрос?