sash_data.right = new FormAttachment (100);
sash_data.top = new FormAttachment (init_percent, 0);
//sash_data.bottom = new FormAttachment (init_percent+2, 0);
sash.setLayoutData (sash_data);
sash.addListener (SWT.Selection, new Listener () {
public void handleEvent (Event e) {
Rectangle sashRect = sash.getBounds ();
Rectangle shellRect = parent.getClientArea ();
int right = shellRect.height - sashRect.height - limit;
e.y = Math.max (Math.min (e.y, right), limit);