Uncaught ReferenceError: AssignmentDetail is not defined at HTMLButtonElement.onclick

Could someone tell me why I get that error? I am using Laravel 5.6 and when trying to execute a function through the onclick event of an html button it does not run and in console I get the error Uncaught ReferenceError: AssignmentDetail is not defined at HTMLButtonElement.onclick , this is the code of sight:

@if(count($asignacion)>0)
         @foreach ($asignacion as $asignaciones) 
         <tr>
          <td>{{ $asignaciones->grado." ".$asignaciones->Nombrefun." ".$asignaciones->PaternoFun." ".$asignaciones->MaternoFun }}</td>
          <td>{{ $asignaciones->Gtesorero." ".$asignaciones->NombreTes." ".$asignaciones->PaternoTes." ".$asignaciones->MaternoTes }}</td>
          <td>{{ $asignaciones->Oficina }}</td>

          @if($asignaciones->estadoAsignacion<=1) 
            <td><h3><span class='badge badge-pill badge-danger'>abierto</span></h3></td>;
            <td><button type='button' class='btn btn-success btn-md' data-toggle='modal' data-target='#AsignacionModal' value='{{$asignaciones->id_asignacion}}' onclick='AddItem(this);' id='{{$asignaciones->id_asignacion}}'><span class='fas fa-plus'></span>  Item</button>
            <button type='button' class='btn btn-primary btn-md' onclick='AsignacionDetalle(this);' data-toggle='modal' data-target='#DetalleAsignacionModal' value='{{$asignaciones->id_asignacion}}'><span class='fas fa-eye'></span>  Ver</button>
            <button type='button' class='btn btn-danger btn-md' value='{{$asignaciones->id_asignacion}}' onclick='CerrarAsignacion(this);' id='cerrar'><span class='fas fa-times'></span> Cerrar</button></td>
          @else
            <td><h3><span class='badge badge-pill badge-success'>cerrado</span></h3></td>
            <td><button type='button' class='btn btn-primary btn-md' onclick='AsignacionDetalle(this);' data-toggle='modal' data-target='#DetalleAsignacionModal' value='{{$asignaciones->id_asignacion}}'><span class='fas fa-eye'></span>  Ver</button></td>
          @endif
         </tr>
         @endforeach
    </tbody>
 </table>
    {!! $asignacion->render() !!}
   @else 
<div class="alert alert-info" role="alert" style="padding-top: 20px">
No existen Asignaciones para mostrar
</div>
   @endif