How does Jsifame interact with functions in the parent window?

Page A contains an iframeSyntaxHighlighter. all (); info & nbsp; | & nbsp; Security & nbsp; | & nbsp;

Page A contains an iframe. Some html code is as follows:

[Html]
& Nbsp; <br/> the js script section on page A is as follows: </p> <p> www.2cto.com <br/> [javascript] <br/> var System ={& nbsp; & nbsp; <br/> & nbsp; CloseFrame: function () {& nbsp; <br/> & nbsp; & nbsp; try {& nbsp; <br/> & nbsp; & nbsp; var frames = document. getElementById ("ifmApp"); & nbsp; <br/> & nbsp; & Nbsp; & nbsp; var AppHelper = frames. contentWindow. appHelper; & nbsp; <br/> & nbsp; & nbsp; if (AppHelper! = Null & typeof (AppHelper) = "object" & typeof (AppHelper. closeQuery) = "function") {& nbsp; & nbsp; <br/> & nbsp; & nbsp; & nbsp; if (! AppHelper. closeQuery () return; & nbsp; <br/> & nbsp; & nbsp; & nbsp ;}& nbsp; <br/> & nbsp; & nbsp;} catch (e) {& nbsp; & nbsp; <br/> & nbsp; & nbsp; & nbsp ;}& nbsp ;& Nbsp; & nbsp; <br/> & nbsp; System. close (); & nbsp; <br/> & nbsp; & nbsp ;},& nbsp; <br/> & nbsp; Close: function () {& nbsp; <br/> & nbsp; document. body. removeChild (ifrm); & nbsp; <br/> & nbsp; & nbsp ;}& nbsp; & nbsp; <br/> }; & nbsp; </p> <p> B. asp page with js functions: </p> <p> [javascript] <br/> var Apphelper ={& nbsp; <br/> & n Bsp; & nbsp; CloseQuery: function () {& nbsp; <br/> & nbsp; & nbsp; if (val = "1") return true; & nbsp; <br/> & nbsp; & nbsp; return false; & nbsp; <br/> & nbsp; & nbsp ;}, & nbsp; <br/> & nbsp; close: function () {& nbsp; & nbsp; <br/> & nbsp; if (parent! = Null & typeof (parent) = "object") {& nbsp; & nbsp; <br/> & nbsp; & nbsp; var System = parent. system; & nbsp; <br/> & nbsp; & nbsp; if (System! = Null & typeof (System) = "object") {& nbsp; <br/> & nbsp; & nbsp; if (System. close! = Null & typeof (System. close) = "function") {& nbsp; <br/> & nbsp; & nbsp; & nbsp; System. close (); & nbsp; <br/> & nbsp; & nbsp; & nbsp; return; & nbsp; <br/> & nbsp; & nbs P; & nbsp; & nbsp; & nbsp ;}& nbsp; <br/> & nbsp; & nbsp; & nbsp ;}& nbsp; <br/> & nbsp; & nbsp; & nbsp ;}& nbsp; <br/> & nbsp; & nbsp; & nbsp ;}& nbsp; & nbsp; <br/>}; & nbsp; </p> <p> parent page, by calling your System. closeFrame to call the function Apph in ifrme Elper. in CloseQuery <br/> Ifame, you can call your Apphelper. close function to call System in the parent window. close </p> <p> Of course, there is A premise to implement such A simple call, that is, A and B need the same domain. <Br/> from the pure land of the soul </p>