how to map from a ViewModel to Model

i have to model and viewModel like this

public class Estate:BaseEntity
{

    public virtual BaseInformation floorType { get; set; }

}

 public class EstateViewModel:BaseEntityViewModel
{

    public  long floorType { get; set; }

}

and i wrote the code in controller like this :

[HttpPost]
    public long save(EstateViewModel estateViewModel)
    {
        Estate entity = new Estate();
       BaseInformation bi = new BaseInformation();
       bi.id = 1;
       entity.floorType = bi;
       EstateViewModel ev = new EstateViewModel(); 
                 Mapper.CreateMap<EstateViewModel, Estate>();
                 var model = AutoMapper.Mapper.Map<EstateViewModel,Estate>(estateViewModel);

            return estateRepository.save(entity);
    }

when call the action autoMapper give an error like this : An exception of type 'AutoMapper.AutoMapperMappingException' occurred in AutoMapper.dll but was not handled in user code

please help how can fix it thanks

via Chebli Mohamed