MSFlexGrid Tab Problem

Users need to be able to enter data in a 1 column grid and have the ability to tab through the rows. I have this working. The problem: Once they start tabbing through the rows on the grid, they must go through all of the rows before they can exit the form. Clicking on the Close button just continues the focus through the remaining grid rows. I am using code provided by Microsoft at support.microsoft.com/kb/241355. Does anyone know how I can trap this?

Thanks in advance for any assistance.