The readyState property indicates the current state of the XML document.

This property is read-only and returns one of the following values indicating the instantiation and download state of the XML document.

• LOADING(1)
  loading in progress; reading persisted properties but not yet started parsing data. For purposes of the standard readyState definitions, data should be considered equivalent to BLOB properties.
• LOADED(2)
  reading of persisted properties completed; reading and parsing data, but the object model is not yet available.
• INTERACTIVE(3)
  some data has been read and parsed, and the object model is available on the partially received data set. The object model at this stage is read-only.
• COMPLETED(4)
  the document has been completely loaded, successfully or unsuccessfully.

This property is a Microsoft extension to the W3C DOM.