How can I switch off the zoomslider reset?

Hello,
I would like to switch off the "overzoom" effect, when the slider value is set back to zero.
Please, give mi a hint, how can I prevent this event as setting the sliders value continuously to 99 or 100 won't help. I think it is hidden somewhere in the modified jquery-ui.js, but it is not in a human readable format (at least for me :-)).
Thank you very much for your help in advance! Br, Peter