Indicates whether a Pop-up Window Show Action’s pop-up Window can be resized by an end-user.
true if an end-user can resize the current Pop-up Window Show Action’s pop-up Window; otherwise, false.
This property is processed by built-in Action Containers that visualize Pop-up Window Show Actions. You can implement a cusotm Action Container that will not consider this property and will always display a nonsizable pop-up Window.
By default, the IsSizeable property is set to true.