increasing line height and scrollbar

The vertical scroll bar does not show up when I resize the line height, even after a refresh. Le line has the correct height but the scrollbar does not show and thus many lines are not reachable.

Any idea?
var n= 3;
grid.getRowTemplate().setStyle("height",n+"em");
grid.refresh();

If you want to change the height of the rows dynamically - use setRowHeight(num) method, which triggers recalculation of scroll heigth and position.

I can see it but that 's the point : it is not what I need.

AND "EM" UNIT IS NOT A FEATURE IN A FUTURE RELEASE THE USE OF THIS GRID WILL BE DEFINITIVELY OUT OF THE LOOP.