You can view the document window lattice.Using the grid, but is useful for drawing the holes line.
To set the grid is done using a grid panel.
Main menu "Format" "Grid" "Show Grid Options" selected.
Set the grid spacing by using the scroll bar.
Set the grid color using the color well.
"Snap to Grid" is enabled, and you can move an object in units of grid spacing.
Main menu "Format" "Grid" "Grid Selected Graphics" command and can fit on the grid object.
You can also conduct a drawing on a grid.