let f ?bio request =
% begin match Dream.session "nick" request with
% | None -> 
not logged in
% | Some nick ->
%begin match bio with 
%   | None ->
% let bio = match User.get_bio nick with
%    | Ok bio -> bio
%    | Error e -> e
%in
                <%s  Format.sprintf "Hello %s !" nick %>
    <%s! Dream.form_tag ~action:"/profile" request %>
      <div class="mb-3">
        <label for="bio" class="form-label">Bio</label>
        <input name="bio" type="text" class="form-control" id="bio" aria-describedby="bioHelp" value="<%s bio %>" </input>
        <div id="bioHelp" class="form-text">Who are you?</div>
      </div>
      <button type="submit" class="btn btn-primary">Save</button>
    </form>
%   | Some bio -> 
% begin match User.update_bio bio nick with
%    | Ok () -> 
    Bio updated !
%    | Error e -> 
    <%s e %>
%    end;
%   end;
%end;