Mathcad 14 List Box Output

Hello all,

I am relatively new to Mathcad 14. The problem I am having is with List Boxes.

In the attached document, you can see two list boxes. The second reads the output from the first and displays a different result based on what is read in from the first list box. The problem is that the outputs in list box 2 accumulate, as opposed to being replaced. I have tried solving this problem using the ResetContent function, but then I was unable to make the selection (it would not stay highlighted).

I would greatly appreciate any help,

Carl