Assistance on Query

Hi People, I would like some assistance on the following scenario. I have to pull out all records for a particular userid (easy enough) and then only show those entries where the follwing occurs. These records from the table will contain either an entry in the services_type field or the non_services_type field. What I need to do is show only those where the number of consecutive records that contain an entry in the non_services_type field is greater than or equal to 3 so example:- record 1 contains an entry in non_services_type record 2 contains an entry in services_type record 3 contains an entry in non_services_type record 4 contains an entry in non_services_type record 5 contains an entry in non_services_type record 6 contains an entry in services_type so I would need to display records 3,4,5 only Can anyone assist me with this? Cheers, Shannon