Well generally, what we do is this. We first of all, we know that if you're in fact primarily having difficulty because of bone loss, the ordinary physiologic bone loss,and your vitamin D and calcium are corrected and there's nothing else wrong with you. The odds are overwhelming that if you take one of the prescription meds, it's going to work.The way that we gauge that it's working typically is by doing a follow up bone density.And that's why it's nice to have a baseline bone density prior to treatment, of the, baseline density of the spine and the hip.Generally speaking, if it's a good quality test and you can believe it because it's done on the same machine in the same place and you're stable, or maybe even a teeny bit higher, the drug is working.Patients sometimes say, oh, it didn't go up, or oh, I didn't gain any ground.What you have to understand is the way the drugs work primarily is to improve the quality of your bone, which the test can't measure.The bone density test isn't really telling us a whole lot about the bone quality.Some people will in fact get a small increase in the bone density. Others won't, they'll just get stabilization. Either is a sign that the drug is working and that your bones are stronger.Getting stronger bones is the goal.