Iframe communication with main Edge composition

Hello, I have some trouble to acces a function that if in my main Edge animation, from an iframe

in my main Edge composition I have this function in document.compositionready

function Open360() {

    alert("Open360 // ");

}

sym.setVariable("Open360", Open360);

//sym.getVariable("Open360")("Saintmedard");

In my iframe I tryed differents things but can make it work

$.Edge.getComposition('EDGE-2349403176').getStage().getVariable("Open360")(); // doesn't wok

Edge.getComposition('EDGE-2349403176').getStage().getVariable("Open360")("Saintmedard"); // doesn't wok

AdobeEdge.getComposition('EDGE-2349403176').getStage().getVariable("Open360")("Saintmedard "); // doesn't wok

any idea?

thanks for your help