Calculates Holm's sequential Bonferroni method to maintain error rates at a desired alpha level.This program calculates a modified Bonferroni method proposed by Holm (1979) that is more powerful than the traditional Bonferroni approach but maintains experimentwise error rate. Termed a sequentially-rejective Bonferroni method (Shaffer, 1995), it may reject some hypotheses not rejected by the simple Bonferroni method.