Запись двусвязного списка в файл и чтение

  TPElem = ^TElem;
  TElem = record
    Data : integer;
    PNext : TPElem;
    PPrev : TPElem;
  end;
 
  TList = record
    PFirst : TPElem;
    PLast : TPElem;
  end;

procedure Ttable.writefile(filename:string; Edit1: TEdit;Edit2: TEdit;Edit3: TEdit;Edit4: TEdit;Edit5: TEdit);
begin
  if count=0 then
  begin
  AssignFile(SaveF,filename);
  if FileExists(filename) then
     reset(SaveF);
  end;
  inc(count);
  New(PElem);
PElem^.name:= Edit1.Text;
PElem^.id:=strtoint(Edit2.Text);
PElem^.ves:=strtofloat(Edit3.Text);
PElem^.count:=strtoint(Edit4.Text);
PElem^.namefirma:=Edit5.Text;
write(SaveF,Pelem^);вот тут не знаю как записывать 
showmessage('Çàïèñü óñïåøíî çàïèñàíà â ôàéë');
end;

procedure Ttable.createfile(filename:string);  //ñîçäàíèå ôàéëà
var
SaveF:  File of Detal;
begin
    AssignFile(SaveF,filename);
    rewrite(SaveF);
    count:=0;
  List.PFirst := nil;
  List.PLast := nil;
end;

Type  //ñòðóêòóðà  äâóõñâÿçíîãî ñïèñêà
 
  TPElem = ^Detal;
  Detal = record
  name:string[10];
  id:integer;
  ves:real;
  count:integer;
  namefirma:string[10];
  PNext : TPElem;
  PPrev : TPElem;
  end;
 
  TList = record
    PFirst : TPElem;
    PLast : TPElem;
  end;

var
 count:integer;
  List : TList;
  PElemsave,PElemload : TPElem;
procedure Ttable.createfile(filename:string);  //ñîçäàíèå ôàéëà
var
SaveF:  File of Detal;
begin
    AssignFile(SaveF,filename);
    rewrite(SaveF);
    count:=0;
  List.PFirst := nil;
  List.PLast := nil;
end;
 
procedure Ttable.writefile(filename:string; Edit1: TEdit;Edit2: TEdit;Edit3: TEdit;Edit4: TEdit;Edit5: TEdit);
begin
  if count=0 then
  begin
  AssignFile(SaveF,filename);
  if FileExists(filename) then
     reset(SaveF);
  end;
  inc(count);
  New(PElemsave);
PElemsave^.name:= Edit1.Text;
PElemsave^.id:=strtoint(Edit2.Text);
PElemsave^.ves:=strtofloat(Edit3.Text);
PElemsave^.count:=strtoint(Edit4.Text);
PElemsave^.namefirma:=Edit5.Text;
write(SaveF,PElemsave^);
showmessage('Çàïèñü óñïåøíî çàïèñàíà â ôàéë');
end;
 
procedure Ttable.AddL(var aList : TList; const aPElem : TPElem);
begin
  if aPElem = nil then Exit;
 
  aPElem^.PNext := nil;
  aPElem^.PPrev := nil;
  if aList.PFirst = nil then begin
    aList.PFirst := aPElem;
    aList.PLast := aPElem;
  end else begin
    aList.PLast^.PNext := aPElem;
    aPElem^.PPrev := aList.PLast;
    aList.PLast := aPElem;
  end;
end;
 
 
procedure Ttable.readfile(filename:string;StringGrid1: TStringGrid);
var
i:integer;
begin
CloseFile(saveF);
AssignFile(SaveF,filename);
if FileExists(filename) then
reset(SaveF);
 
For i:=0 to StringGrid1.RowCount-1 do
 StringGrid1.Rows[i].Clear;
For i:=0 to StringGrid1.ColCount-1 do
 StringGrid1.Cols[i].Clear;
 StringGrid1.Cells[1,0]:='Íàèìäåò';
 StringGrid1.Cells[2,0]:='Èíäèâèäíîìåð';
 StringGrid1.Cells[3,0]:='Âåñ';
 StringGrid1.Cells[4,0]:='Êîëäåòàëè';
 StringGrid1.Cells[5,0]:='Ïîñòàâùèê';
 
for i:=0 to count-1 do
    begin
  new(PElemload);
 read(SaveF,PElemload^); //÷èòàåì çàïèñè èç ôàéëà â ìàññèâ
 AddL(List, PElemload);
 StringGrid1.Cells[0,i+1]:=inttostr(i+1);
 StringGrid1.Cells[1,i+1]:=PElemload^.name;
 StringGrid1.Cells[2,i+1]:=inttostr(PElemload^.id);
 StringGrid1.Cells[3,i+1]:=floattostr(PElemload^.ves);
 StringGrid1.Cells[4,i+1]:=inttostr(PElemload^.count);
 StringGrid1.Cells[5,i+1]:=PElemload^.namefirma;
 
 
    end;
 
 
 
 
end;