Easy Helper functions for PostMessage

Makes managing messaging to frames alot easier.
WebWorkers too.
Uses JSON.stringify and parse to allow you to send objects, simple string commands, or both.

/**************************
 Message Passing to frame
*************************/

function postMsgToFrame(cmd, msg) {
 var frame = document.getElementById("myIframe");
 if (!msg || msg == null || msg == undefined) {
 msg = null;
 }
 var packet = { "cmd": cmd, "msg": msg }
 console.log("sending to client", JSON.stringify(packet));
 frame.contentWindow.postMessage(JSON.stringify(packet), "*");
}


/**************************
 Message recieving from frame
**************************/

function recieveMessage(e) {
 var packet = JSON.parse(e.data);
 console.log("new cmd packet", packet);
 if (packet.cmd == something) {
 doSomething();
 } else if (packet.cmd == something_else) {
 doSomethingElse();
 } else {
 console.warn('bad packet', packet);
 }
};

window.addEventListener("onmessage", recieveMessage, false);