perCase() : 'GET',
callback = settings.callback ? settings.callback : false,
data = settings.data ? settings.data.toString() : '',
xhr_done = settings.xhr_done ? settings.xhr_done : null,
xhr;
// xhr in progress or url not provided -> exit
if ( !( (xhr_done == true || xhr_done == null) && url ) ) return;
if ( typeof XMLHttpRequest !== 'undefined' )
{
xhr = new XMLHttpRequest();
}
else
{
try
{
xhr = new XMLHttpRequest("MSXML2.XmlHttp.5.0") || new XMLHttpRequest("MSXML2.XmlHttp.4.0") ||
new XMLHttpRequest("MSXML2.Xm