Right, it's not directly related to Web services. This is actually a follow up on my previous question about SPCascadeLookups. I was thinking that I could memorize the first selection, and reinject it after a user makes a second selection.
I am sure SPServices has functions that are not exposed in the documentation and run under the hood, so I thought I'd try my luck!
Doing this for a single lookup is fine, but I am not sure how to tackle it for a multiple lookup. I'll give it a try.
Thanks for the quick reply Marc.