General Studies · Floor or Box Puzzle

Seven boxes, E, F, G, H, I, J and W, are kept one over the other but not necessarily in the same order. Only one box is kept above J. Only three boxes are kept between E and J. I is kept at one of the positions below E. Only W is kept between J and F. H is kept at one of the positions above J. How many boxes are kept between I and H?