if you are using IE6
click at top of IE6, tools
click internet options
click content
click autocomplete
click clear forms and clear pwords

above only web address and user names and passwords on forms should be ticked

if you are using SAFARI on the MAC,
go to RESET SAFARI in the Safari column of the top tool bar.

for Firefox or Mozilla
menu click 'tools'
click 'clear private data'
tick 'saved forms and search history'
then click the 'clear private data now' button