Httpxmlrequest operations and attributes in Ajax

XMLHttpRequest operation
Abort () stops the current request
GetAllResponseHeaders () returns all HTTP Request Response Headers as key/value pairs.
GetResponseHeader ("Header") returns the string value of the specified header.
Open ("method", "url") creates a call to the server. The methed parameter can be get, post, or put. URL parameters can be relative URLs or absolute URLs. This method also includes three optional parameters.
Send (content) sends a request to the server
SetRequestHeader ("Header", "value") sets the specified header to the provided value. Before setting any header, you must call open ()

XMLHttpRequest attributes
Onreadystatechange triggers this event when each state changes. Generally, a JS function is called.
The status of the readystate request. Five values are available: 0 = not initialized, 1 = loading, 2 = loaded, 3 = interaction, 4 = completed.
Responsetext server response, which is a string
Responsexml server response, expressed as XML, which can be parsed as a DOM object
Status Server HTTP status code (200 corresponds to OK, 404 corresponds to not found, etc)
Corresponding text of statustext HTTP status code (OK or not found, etc)