public void setMargin(short margin, double size) {
Margin m = getMarginRec(margin);
if (m == null) {
switch (margin) {
case Sheet.LeftMargin:
_leftMargin = new LeftMarginRecord();
m = _leftMargin;
break;
case Sheet.RightMargin:
_rightMargin = new RightMarginRecord();
m = _rightMargin;