protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            using (WebContext db = new WebContext())
            {
                var Name = validationContext.MemberName;

                if (string.IsNullOrEmpty(Name))
                {
                    var displayName = validationContext.DisplayName;

                    var prop = validationContext.ObjectInstance.GetType().GetProperty(displayName);

                    if (prop != null)
                    {
                        Name = prop.Name;
                    }
                    else
                    {
                        var props = validationContext.ObjectInstance.GetType().GetProperties().Where(x => x.CustomAttributes.Count(a => a.AttributeType == typeof(DisplayAttribute)) > 0).ToList();

                        foreach (PropertyInfo prp in props)
                        {
                            var attr = prp.CustomAttributes.FirstOrDefault(p => p.AttributeType == typeof(DisplayAttribute));

                            var val = attr.NamedArguments.FirstOrDefault(p => p.MemberName == "Name").TypedValue.Value;

                            if (val.Equals(displayName))
                            {
                                Name = prp.Name;
                                break;
                            }
                        }
                    }
                }

                //  PropertyInfo IdProp = typeof(User).GetProperties().FirstOrDefault(x => x.CustomAttributes.Count(a => a.AttributeType == typeof(KeyAttribute)) > 0);

                //int Id = (int)IdProp.GetValue(validationContext.ObjectInstance, null);

                Type entityType = typeof(User);


                var result = db.Set(entityType).Where(Name + "==@0", value);
                int count  = 0;

                /* if (Id > 0)
                 * {
                 *   result = result.Where(IdProp.Name + "<>@0", Id);
                 * }*/

                count = result.Count();

                if (count == 0)
                {
                    return(ValidationResult.Success);
                }
                else
                {
                    return(new ValidationResult(ErrorMessageString));
                }
            }
        }