trading levels

oil 7-7-10
trading levels lows 66 highs 72,5
R3 71,8
R2 71,2
R1 70,7
N VALUE 70,22
S1 69,47
S2 68,7
S3 67,5

This is today's levels that I use

sell as close to the highest level that is possible
buy as close to the lowest level that is possible
and sometimes it gets a little trade between levels if it feels right for the moment