[ms_access] How do I mone One record at a time through a table?

[bryan.leggo]

Sorry for the simplistic questions again, but how do I move through a 
table one record at a a time so that can check the contents of fields 
as as I go. Here's pseudo-code for what I want:

For I = 1 to NumberOfRecordsinaTable
   Go to Record I
   X = RecordI.Fieldname 1
   Y = RecordI.Fieldname 4
   Z = RecordI.Fieldname 8
NEXT I