Being somewhat stubborn I have spent three days tryimg to make this work. If you think what I'm trying to do is impossible, don't waste any time on it.
I use a 'dummy message box' that is draggable and looks like this:

I merge a group and a transparent field (which is below the group) like this:

I also make one object in the group draggable like this:

All this works well and I'm very satisfied with the result. It works more or less like the TB request/ask system. I would like it to be able to ask for passwords too but so far I haven't managed this. I have tried using one field in the group for normal ask and one for password ask using your makePassword script. I have tried using make password before and after page load. I have also tried using pgGotoURL and a separate html file. I thought this would work but it didn't. Both methods work in a regular non draggable field on the page but fail when this field is part of the draggable group. The symptoms are the same for both methods; the field cannot be seen and cannot receive the focus and significantly its left property becomes 0.
If you think making the password field in this draggable group is impossible, don't waste time on it. I shall have to settle for using a fixed password field.
John
UPDATE: Please ignore all this for the moment. I think I'm nearly there using the pgGotoURL method.