I would like to build a formula for a page I'm building that subtracts the weight field from the last record entered (the current WeighIn) from the previous record entered (last weeks WeighIn), in order to see how much weight was lost or gained. I was told to use the for each record command to iterate and return the values, but I can't seem to figure this out.

I have this variable formula which returns the 3 test records I've inputted.

currentWeight = (Weigh_In[ID != 0].Weight sort by Date_field desc).getAll();

This works... but now what?  I just can't seem to figure this one out.  I have a feeling that though the formula above works to retrieve the values, it isn't what I need to get the values I'm looking for.

Any help appreciated.

Thanks

Michael