As the links I've provided, though just a few, show, many authoritative sources, both monolingual and bilingual, call them input boxes, in HTML, javascript, java, css, ajax, etc. etc. It's not just Microsoft by any means, that was simply meant as an industry standard.<br>"input box" only gets about 5 million Ghits (
http://www.google.com/search?hl=en&rlz=1G1GGLQ_DEDE321&q="in... of which that Microsoft link is just the first.
The WWW Consortium call it an input box too, e.g.:
http://www.w3.org/WAI/UA/TS/html401/cp0102/0102-ONCLICK-MULT...