javascript : this pointer?

[exoscale]

in the following script ~this pointer~(self variable) is used to bind XHR to the object that calls the function. but i am wondering why it is required. anonymous function assigned to the onreadystatechange event method could create a closure that would make xmlHttpReq accessible even XHR is not bound to anything, i've tested this situation if not made some mistake. XHR does not seem to be destroyed when the function exits as its called asynchronously. It does not make sense in this simple code but may be meaningfull in an OO approach as multiple functions access the XHR object. Am i right? So what is the semantic of this usage? thanks function xmlhttpPost(strURL) { var self = this; self.xmlHttpReq.onreadystatechange = function() { if (self.xmlHttpReq.readyState == 4) { updatepage(self.xmlHttpReq.responseText); } } }http://www.degraeve.com/reference/si...ax-example.php

[Wyatt]

i'm not sure i'm following your question completely, but self=this; creates a local scope instance of "this" so when the function exits, "this" should be unchanged, which is what i think you said is the behavior you are experiencing.