Combo Box Control - Button Is Pressed, The Current Data Is Stored Into The Array?

I am working on an inventory managment project for a lumber mill. I am currently writing a piece of software to be used on the sorting section of the mill. The problem I am having is when a stick of lumber needs to be cut down in lengt. My current setup has a combo box that is populated with lengths of lumber that we might have (2' - 60'), a "Add" button and a data control (homemade solution with lots of labels, and panels).

The user will scan a tag into the system, and the system pulls up the info from the db. If the piece need to be cut, the user will select the length of the cut, and click the add button. The system will then populate the first line of the data control with the info from the cut (previous piece info, and new length). It also populates a pieceObject struct. This happens for any additional cut that might happen.

The problem I am having is that everytime I press the "Add" button, the length variable will update every length in the piece array.

Here is a section of the code I am dealing with.

piece is a lumberPiece, and pieceAry is a array of 15 lumberPieces

Each time the add button is pressed, the current data is stored into the array, and then the pieceNum is incremented.

[code]...