public function postGuardar()
 {
     $bandera = false;
     $id = Input::get('idQues');
     $ans = Input::get('res');
     $answers = Answer::all();
     $question = Question::find($id);
     $cantidad = Question::count();
     foreach ($answers as $a) {
         if ($a->id_question == $id) {
             $bandera = true;
             $answer = $a;
             break;
         }
     }
     if (!$bandera) {
         $answer = new Answer();
         $answer->id_question = $id;
         $ids = Auth::id();
         $student = Student::where('id_user', '=', $ids)->get()->first();
         $answer->id_student = $student->id;
         $answer->answer = $ans;
         $answer->result = QuestionsController::verifyAnswer($question, $ans);
         $answer->save();
     } else {
         $answer->result = QuestionsController::verifyAnswer($question, $ans);
         $answer->answer = $ans;
         $answer->save();
     }
     if ($cantidad == $id) {
         return Redirect::to('questions/exam?endTest=yes');
         //"holi ".$id." ".$ans;
     } else {
         if ($cantidad > $id) {
             return Redirect::to('questions/exam?numberQIn=' . ++$id);
         }
     }
 }