Thru nxopen, is it possible to disable the UDO links temporily? I have a UDO linked to few expressions. Thru nxopen I am editing the expressions and doing some operations. But the UDO triggeres automatically as the expression changes. I want to preven the UDO callbacks when I edit expressions programatically. But I want the linkage of UDO with expression, when the expression is editted in GUI.