Save values from Delphi to Disk: "Save" and "Save as"

Question

I am creatinga program that saves some information (usually edit fields) on the disk using the following code:

  procedure TForm1.ToolButton3Click(Sender: TObject);   
    begin    
    if  Savedialog1.Execute then
         begin
            AssignFile(myFile, save.filename);
            ReWrite(myFile);
            customer.Name:=name.text;
            customer.LastName:= LastName.Text;
           //[...] <-- much more fields
            Write(myFile, customer);
            CloseFile(myFile);  
            end;

end;

And this code to open:

procedure TForm1.ToolButton12Click(Sender: TObject);
begin
  if opendlg.execute then begin
     Form1.Caption := 'Program Name '+' - '+extractfilename(Opendlg.FileName);

     if FileExists(opendlg.filename) then
    begin
     AssignFile(myfile, opendlg.filename);

    end;
    // Reopen the file in read only mode
   FileMode := fmOpenRead;
   Reset(myFile);

   // Display the file contents
   while not Eof(myFile) do
   begin
     Read(myFile, customer);

   Name.text:=customer.Name;
   LastName.Text:=customer.LastName; 
   //[...] <-- much more fields
end;
end;
end;   

I do not know if the method is the more accurate but it is what i'm using =(. So how can I make by clicking on the save button I just update the file that was previously saved without the need to reopen the save dialog? Thanks!

Answer 1

Like this:

procedure TForm1.ToolButton3Click(Sender: TObject);   
begin    
  if SaveDialog1.FileName = '' then
  begin
    if not SaveDialog1.Execute then
      Exit;
    end;
  end;
  AssignFile(myFile, SaveDialog1.FileName);
  ...
end;