Could you point what must to be adjusted at this view code to avoid the form beeing submited if the modal's textbox is empty?

<?

<div class='row'>
    <br/>
    <div class="well well-lg text-center">
        <h1>Fotos</h1>
    </div>
</div>

<input type='hidden' id='pagina' value='1'/>

<div class="container">
    <div class="row">
    
          <!--div class="panel panel-primary"-->
          <div class="panel panel-default">
          
            <div class="panel-body">
                <div class=" col-md-12 col-sm-12"> 
                      <div class='row'>
                      
                         <div class="col-sm-12 col-md-6">
                          <div class="btn-group" role="group">
                            <button type="button" class="btn btn-primary" onclick="Xxxxx.vitrine.minhasfotos();">
                              <i class="fas fa-video" aria-hidden="true"></i> Minhas Fotos
                            </button>
                          </div>
                        </div>
                        
                         <div class="col-sm-12 col-md-3">
                          <div class="btn-group" role="group">
                            <button type="button" class="btn btn-primary" onclick="Xxxxx.vitrine.todasfotos();">
                              <i class="fas fa-video" aria-hidden="true"></i> Todas as Fotos
                            </button>
                          </div>
                        </div>
                          
                         <div class="col-sm-12 col-md-3">
                          <div class="btn-group" role="group">
                            <button type="button" class="btn btn-primary" onclick="Xxxxx.vitrine.novo();">
                              <i class="fas fa-video" aria-hidden="true"></i> Enviar Foto
                            </button>
                          </div>
                        </div>
                          
                      </div>  
                      
                  </div>
            </div>
        </div>
    </div>
</div>

<div class='row' id="lista"></div>

  <div class='row'>
    <div id="midiaList">
      @include('vitrines.fotos')
    </div>
  </div>


<!-- Modal -->
<div class="modal fade" id="mEditor" tabindex="-1" role="dialog" aria-labelledby="mEditorLabel">
  <div class="modal-dialog modal-lg" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        <h4 class="modal-title" id="mEditorLabel">Nova Foto</h4>
      </div>
      <div class="modal-body row">
            <input type='hidden' value="0" id='id' name='id'>

            <div class='col-md-7'>
  
                <div class='col-md-12 form-group'>
                    <label for='title'>Título</label>
                    <input type='text' id='title' name='title' class='form-control'/>
                </div>

                <div class='col-md-12 form-group'>
                    <label for='description'>Descrição</label>
                    <input type='text' id='description' name='description' class='form-control'/>
                </div>
                
            </div>

            <div id='box-video' class='col-md-5 text-center'>
            
                <img id='srcVitrine' src=''>
                

                <div class='col-md-12 form-group'>
                    <label for='titulo'>URL (Foto/ Imagem):</label>
                    <div class="input-group">
                        <input type='text' id='url' name='url' disabled class='form-control'/>
                        <span class="input-group-btn">
                            <button class="btn btn-primary" type="button" onclick='Xxxxx.vitrine.subirVideo();'><i class="fa fa-camera"></i></button>
                        </span>
                        <input type='file' id='file' name='file' style='display:none;'/>
                    </div>
                </div>
            </div>
      </div>

      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal"><i class="fas fa-times" aria-hidden="true"></i> Fechar</button>
        
		
		<button type="button"  id="btnSubmit" class="btn btn-primary" onclick="Xxxxx.vitrine.salvar();"><i class="fas fa-hdd" aria-hidden="true"></i> Salvar</button>
      
	  
	  </div>
    </div>
   
  </div>
</div>

<script>
  var jqXHRData;
  $(document).ready(function() {
    
    var pars = {
        _token:$('input[name="_token"]').val()
    };

       var resultImageUpload = function (data) {
        if (!data.result.erro) {
            localizacao = data.result.retorno.localizacao;
            $('#url').val(localizacao);
            
            $('#srcVitrine').attr('src', localizacao);


            return false;
        } else {
          xxx.openModalCustom("Erro",'Erro ao subir vídeo.', "Entendi", "error");
          return false;
        }
        else
        {

// ---- ADJUST ---This function is called but even returning false the form is submited with success 
            $(function() {  
                $('#btnSubmit').click(function() {  
                    var txt = $('#title');  
                    if (txt.val() != null && txt.val() != '') {  
                        alert('you entered text ' + txt.val())  
                    } else {  
                        alert('Please enter text')  
                        return false;   
                    }  
                })  
            });  
       
        }
    
    };

    var failImageUpload = function (data) {
          if (data.files[0].error) {
              Xxxxx.openModalCustom("Erro",'Erro ao subir vídeo.', "Entendi", "error");
              return false;
          }
    };

    Xxxxx.InitFileUpload("file", "/vitrine/salvarVitrine", pars, resultImageUpload, failImageUpload);

   // Limpa a Modal
   $(".modal").on("hidden.bs.modal", function(){
        $(".modal-body input").val("")
    });


    $("#file").change(function () {
        if (jqXHRData) {
            jqXHRData.submit();
        }
        return false;
    });
  })
</script>
@endsection