Using the positioning and sizing functions for the contained windowinstance may have unpredictable results. If resizing of the windowinstance is
desired, the size of the parent subwindow control should be changed instead.
A reference to the contained windowinstance object is available from the script environment of the parent subwindow control through the variable
subwindow. In the other direction, a reference to the parent subwindow control is available from the contained windowinstance object through the
If present, this function is executed when the window instance contained in the subwindow has been created.