Grid to separate the column values.
Access / Assign
A grid separates the column values by horizontal and/or vertical lines from each other.
If the access returns NULL_OBJECT, the grid is used from the bBrowser.
So that changes at this access are shown also in the browser, the column must be redrawn with the method bBrowser:Redraw(). This is only necessary if the column is inside the visible area of the browser.