tab index of address bar

[Amy]

When a dropdown list is posted back the tab index starts at 0 again. I can manage all my other fields (though it is painful) but the address bar is still the next tab position. How do I I remove the IE address bar from the tabb index or is there away around using " post back " . One dropdown list is filled based on selection of another.

Any help would be great I am just beginning to use .net