I want to update a table row and I have a following Code

void updatePrimaryPaymentAndSecondaryPaymentSourceTypes()

{

LookUpDetails lookUpDetail = new LookUpDetails();

var repo = new SimpleRepository("E2Lending", SimpleRepositoryOptions.RunMigrations);

lookUpDetail = repo.Single(80);

lookUpDetail.Col1Value = "My Checking Account";

repo.Update(lookUpDetail);

}

public class LookUpDetails

{

```
[SubSonicPrimaryKey]

public int LookUpDetailId {get; set;}

public int LookUpGroupId { get; set; }

public string Code { get; set; }

public int SortOrder { get; set; }

public string Col1Value { get; set; }

[SubSonicNullString]

public string Col2Value { get; set; }

[SubSonicNullString]

public string Col3Value { get; set; }

[SubSonicNullString]

public string Col4Value { get; set; }

[SubSonicNullString]
public string Col5Value { get; set; }

public DateTime  CreatedOn { get; set; }

public string CreatedBy { get; set; }

public DateTime ModifiedOn { get; set; }

public string ModifiedBy { get; set; }

public Boolean IsActive { get; set; }

```

}

When I execute then repo.Update(lookUpDetail); shows me Null reference Exception.
Can you please tell me How I will be able to update a single record in a table?

Regards