[jQuery] Access an object

I have an iframe in a page which has a url of blank.html. In the
parent page I have the following which is an example script from
frameready. The myVariable is passed to blank.html as an object called
frData. What code would I need on blank.html to access\alert
myVariable.

$.frameReady(function(){ $("<div>I am a div element.
"+frData.myVariable+"</div>").prependTo("body");}
, "top.mainFrame"
, { data:{myVariable: "I am data passed to this frame"}
, load: [
{type:"script", id:"_fr", src:"/js/myscript.js",
test:"myFunction"},
{type:"stylesheet", id:"_ss", src:"mycss.css"}
] }
);

Thanks