This is due to the 'auto-complete' feature of Microsoft, to switch it off, in Internet Explorer 5+ (at least) click on Tools.... then on Internet Options, a new window should open, in there is a tab titled Content, click on that, and you will get, toward the bottom a section entitled Personal Information, with a button saying AutoComplete... click on that button and you can 'clear forms' from there, as well as turning off the auto complete feature by unchecking the boxes and clicking on Ok and Ok again