note Anonymous Monk Right now you consider 4 lines ... soon it may be 6. Plan ahead. Load the lines into an array by pushing them onto the end of it; noting when you've reached end-of-file e.g. if there should be less than 4 lines or you've run out. Each time you loop back, shift the first line off the array and push a new line onto the other end. The lines can be reached directly by indexes 0..3. 1007560 1007560 6