this.readystate == 2 code example

Example: readystate==4

//Ajax 5 states of requests
0   UNSENT  open() has not been called yet.
1   OPENED  send() has been called.
2   HEADERS_RECEIVED    send() has been called, and headers and status are available.
3   LOADING Downloading; responseText holds partial data.
4   DONE    The operation is complete.