Optimal Two-Stage Designs For Phase II Clinical Trials (Richard Simon, Controlled Clinical Trials 10:1-10, 1989) Enter probability of accepting poor drug (alpha) [between 0 and 0.3 only] Enter probability of rejecting good drug (beta) [between 0 and 0.3 only] Enter response probabilty of poor drug (P0) [between 0 and 1] Enter response probability of good drug (P1) [P1 should be greater than P0]