[NIch]

Код:

//----------------------------------------------------
procedure TForm1.MaskEdit2Change(Sender: TObject);
begin
if (maskedit1.text='') or (maskedit2.text='') or (Edit2.text='') then     label10.caption:='Заполните поля';
Button1.Enabled := Length(MaskEdit2.Text) > 3;
if Button1.enabled=false
 then label10.caption:='Минимум 4 символа'
        else label10.caption:='';
end;
//----------------------------------------------------
procedure TForm1.Edit2Change(Sender: TObject);//что это???
begin
 //Должно быть хотя бы так
end;
//----------------------------------------------------
function CheckAllowed(const s:string):boolean;
var
  i: integer;
begin
  Result:= false;
  for i:= 1 to Length(s) do
  begin
    if not (s[i] in ['a'..'z', 'A'..'Z', '0'..'9', '_', '-', '.']) then
    Exit;
  end;
  Result:= true;
end;
//----------------------------------------------------
function IsValidEmail(const Value:string):boolean;
var
  i: integer;
  namePart, serverPart: string;
begin
  Result:= false;
  i:= Pos('@', Value);
  if i = 0 then
    Exit;
  namePart:= Copy(Value, 1, i - 1);
  serverPart:= Copy(Value, i + 1, Length(Value));
  if (Length(namePart) = 0) or ((Length(serverPart) < 5)) then
    Exit;
  i:= Pos('.', serverPart);
  if (i = 0) or (i > (Length(serverPart) - 2)) then
    Exit;
  Result:= CheckAllowed(namePart) and CheckAllowed(serverPart)
end;
//----------------------------------------------------