PostMessage

postmessage.js

var origin = null;

if(window.addEventListener) {
	window.addEventListener('message', onMessage, false);
} else {
	window.attachEvent('onmessage', onMessage);
}

function onMessage(e) {
	if(referer !== undefined && e.origin === referer) {
		origin = e.origin;
		
		var msg = JSON.parse(e.data);
		switch(msg.cmd) {
			case 'size':
				_sendSize();
			break;
			default:
				return e;
				break;
		}
	} else {
		return e;
	}
}

function _getSize() {
	setTimeout("_sendSize()", 200);
}

function _sendSize() {
	var sendTo = origin !== null ? origin : '*';
	var frameHeight = jQuery('body').children().first().height() + 25;
	window.parent.postMessage(JSON.stringify({cmd:'size', value:frameHeight}), sendTo);
}