open()
metode open() untuk membuat koneksi ke server web.

send()
metode send() untuk mengirimkan request ke server web .

abort()
metode ini berguna untuk membatalkan request yang dikirimkan ke sever web.

setRequestHeader()
metode ini untuk mengirimkan header value ke server web (content-type,content-length etc.)

overrideMimeType()
metode ini untuk memberitahukan content type dari response nantinya.

onreadystatechange
melakukan pengecekan nilai readystate

readyState
step dari request yang dilakukan nilainya sbb:

• readyState=0step setelah pembuatan object XMLHttpRequest tetapi belum membuka koneksi ke server web.
• readyState=1step setelah memanggil metode open() tetapi belum memangil metode send().
• readyState=2
  setelah memanggil metode send().
• readyState=3Step dimana koneksi ke web server berhasil dibuat dan mengirimkan request tetapi server belum selesai memproses request tersebut.
• readyState=4
  Step dimana proses di server telah selesai dan response telah diterima.

status
Nilai dari HTTP server status, nilainya sbb:

• 100 - Continue; part of request received
• 101 - OK to switch protocols
• 200 - OK; all requested info returned
• 201 - Created; request filled
• 202 - Accepted; request received
• 203 - Source unknown; info came from 3rd party
• 204 - No new content; nothing to send back
• 205 - Reset content; OK to clear form
• 206 - Request only partially filled
• 301 - Moved permanently; use new URL
• 302 - Moved temporarily; use same URL
• 303 - Redirected
• 304 - Not modified since; use cached copy
• 305 - Use proxy; URL is provided
• 400 - Did not understand request; try again
• 401 - Authorization required; needs password
• 402 - Payment required; needs payment data
• 403 - Request refused; may not give reason
• 404 - Not found; not sure of reason (typo, etc.)
• 406 - Content type not acceptable to request
• 407 - Browser must authenticate itself
• 408 - Timed out; send request again
• 409 - Update conflict; explanation provided
• 410 - Not found; resource permanently gone
• 411 - Content length missing in request
• 412 - Conditions on request failed
• 413 - Request too long to process
• 414 - Resource address too long to process
• 415 - Unsupported media type; bad format
• 500 - Internal server error
• 501 - Server cannot fill request
• 502 - Server cannot process gateway request
• 503 - Server overloaded or service over limits
• 504 - Gateway or proxy server timed out
• 505 - HTTP version not supported in server

responseText
berisi text respnse yang dikirimkan oleh server tersedia jika nilai status success.

responseXML
sama seperti responseText tetapi nilai responsnya dalam format XML.