few years ago, i creates my own clone of ajax component. before i created this script, i accessed all onstart and other events directly in each script. this result in multiple create objcts. after i invesigated a widle known public open source ajax component, i decided to create my own minimized ajax component.
new XMLHttpRequest()
new ActiveXObject("Microsoft.XMLHTTP")
ajax({ url : 'file.php?action=info', success : document_info_success })