Can't figure out the error

[x-ice]

Dim SQLUpdateStr As String
'SQL Update string
SQLUpdateStr = "UPDATE Staff SET Address = @Address, BookingRights = @BookRight," & _
"Contract = @Contract, DOB = @DOB, Forename = @Forename, Gender = @Gender," & _
"LoginRights = @LoginRight, ManageRights = @ManageRight, MemberRights = @MemberRight," & _
"Position = @Position, Postcode = @Postcode, Salary = @Salary, StartDate = @StartDate," & _
"Surname = @Surname, [Telephone Number] = @TelNum"
[B]'Set SQL statements
daStaff.DeleteCommand.CommandText = "DELETE FROM Staff" 'Delete statement
daStaff.InsertCommand.CommandText = "INSERT INTO Staff" 'Insert statement
daStaff.UpdateCommand.CommandText = SQLUpdateStr 'Update statement[/B]

When i run this code i get an error ("Object reference not set to an instance of an object."). I don't know why this error is occuring, but i have found out that the error is in the code i highlighted in bold. Any ideas?