Safari selectedIndex problem in Javascript

Hi,

I've been trying to find a solution to this problem in the Safari support
forums but haven't had any luck so far. In Internet Explorer and
Firefox/Mozilla/Netscape, I can programatically set
"myselectbox.selectedIndex = -1" and when I submit my form, the selectbox
value is passed as null or nothing, which is expected. Safari (the latest
version 2.0.4) sets the selectbox to the first value when I submit my form.
What it really does is, it sets the "selectedIndex" property to 0. It
doesn't understand the "-1" value. Is there a workaround for that in Safari
to mimic the behavior from IE/Firefox/Safari/Netscape or will I just have to
"cheat" and add a blank field in each one of my SELECT boxes.

Thanks a lot!