[Plugin: Multiple Category Selection Widget] Enable parent when child is blank

Hi my friends,

When using the “AJAX Chaining” option, I noticed that parent not appear in the final result.
Example: I have 2 select menu(A->[a,b],B).In “A” I select a parent(cat=54) then I select a child(cat=73). In “B” I no have child so I select someone(cat=22). Then I clic search and the result is cat=73,22
All right that means when I select a child the id of the parent of it is not appear in the result.

Now my problem.
When I leave blank a child the result is nothing.
Example: have 2 select menu(A->[a,b],B).In “A” I select a parent(cat=54) then I leave blank the child(cat=”). In “B” I no have child so I select someone(cat=22). Then I clic search and the result is cat=22

So How I can keep the parent when I leave blank the child ??

I hope somebody understand my problem.
Thanks.

http://wordpress.org/extend/plugins/multiple-category-selection-widget/