cross domain iframe communication in javascript

I have website a and website b. b is present in iframe and it conta开发者_开发百科ins some javascript methods I want to overload those methods.

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Windows postMessage

Cross-domain communication the HTML5 way

An Introduction to Cross-Document Messaging in Internet Explorer 8

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Also check out http://easyxdm.net a javascript library for cross domain messaging.

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I think it's much better to do it with Node.Js.You install it to your server and you can do a lot of server thing and more with it