[muppett]

Gracias x su ayuda ya resolvi el problema

Código Delphi [-]
var
  f: TextFile;
  begin                    { open a text file }
    AssignFile(f, 'c:\a.txt');
    Append(f);
    Writeln(f,edit1.text);
    Flush(f);  { ensures that the text was actually written to file }
    CloseFile(f);
  end;

este es el codigo correcto x si a alguien le sirve