How to reorder lines in a list field

[André Bisseret]

Bonjour,

I am trying to get a list field where it would be possible to reorder  
the lines.
(is there somewhere any tutorial or any solution on this?)

I started from a script from Éric Chatonet that allow moving lines  
from field1 to field2, modifying it to drag lines in one field only.

I succeeded in a test stack:  in a list field, all works as expected  
with a dragImage).

My problem is that when I put exactly the same script in a field of an  
app. I am developing, it does not works any more:
The dragged line is deleted when releasing the mouse (except if I drag  
outside the field and then back in it: then that works!!!!

I am fighting with that for hours now, and can't find what is wrong.

My last surprise is that if I don't create (set) any dragImage, then  
all works as expected.

I am getting crazy
The worst thing is that the same script works well in a field on my  
test stack and not on the field on my other stack (the two fields have  
exactly the same properties).

Any idea on what could be wrong?

Thanks a lot in advance

Best regards from Grenoble

André