Resizing background grid

Size of grid in the background
I have an almost perfect swf for my needs; [color=#22229c]www.avgifter.com/forum/graftest2.asp[/color].
My problem as a complete newbie on Flash is that I have no clue of how to change size of the grid in the background. I want the bars to reach higher in the diagram without just manipulate the values. The latter is done in the example.

What should I look for?