XMLHttpRequest use, works only if url is on same site. checklogin.php give <KO/> if login è fails <OK>XXX</OK> with XXX id of user when login è is ok
I tried both SAX and DOM, for parsing an XML file, difference in time performance is huge, from 4 hours (DOM) to 9 seconds (SAX).
Different interface bring to different complexity of code, but all depends from the point of view