About AutoComplete
Microsoft Office InfoPath 2003 uses the AutoComplete feature provided by Internet Explorer. AutoComplete saves previous entries you've typed into fields when filling out a form. If Autocomplete is turned on and enabled for a field on the form, when you type the first few characters into that field, AutoComplete lists possible matches from entries you've typed before. You can then insert the entry you want, or if none of the suggestions match what you are typing, you can continue typing into the field.