I am trying to create a weight loss spreadsheet. Column B has dates in
ascending order, and column c has current day's weight. I want to display
the weight corresponding with the max date that has a weight value greater
than zero.

As weight values are entered, I want the field to automatically update.

On Feb 1, the 192 should show. On Feb 2, the 191 should show. On Feb 3,
the 190 should show. On Feb 4, whatever the user inserts should show.

Spreadsheet Looks like this:

Column B Column C
02/01/2008 192
02/02/2008 191
02/03/2008 190
02/04/2008 <blank value
02/05/2008 <blank value