XMLHttpRequest Methods and Properties
abort() - Stops the current request.
getAllResponseHeaders() - Returns the response headers as a string.
getResponseHeader("headerLabel") - Returns a single response header as a string.
open("method", "URL"[, asyncFlag[, "userName"[, "password"]]]) - Initializes the request parameters.
send(content) - Performs the HTTP request.
setRequestHeader("label", "value") - Sets a label/value pair to the request header.
onreadystatechange - Used to set the callback function that handles request state changes.
readyState - Returns the status of the request:
0 = uninitialized
1 = loading
2 = loaded
3 = interactive
4 = complete
responseText - Returns the server response as a string.
responseXML - Returns the server response as an XML document.
status - Returns the status code of the request.
statusText - Returns the status message of the request.
