问如何使包含在此函数中的变量成为全局变量？

EN

 function getStuff(num, onContents){
 $.getJSON('http://whateverorigin.org/get?url=' + encodeURIComponent('http://catholic.com/api-radio/' + num) + '&callback=?', function(data){
   //call the oncontents callback instead of returning
   onContents(data.contents);
 });
 }

 //when calling getstuff, pass a function that tells what to do with the contents
 getStuff(6387, function(contents){
 var res = (contents);
 //I'm not going to store res in window.myShows, instead I'm adding the test JSON
 window.myShows = [{
    "from": "Steve Jobs",
    "subject": "I think I'm holding my phone wrong :/",
    "sent": "2013-10-01T08:05:59Z"
 },{
    "from": "Ellie Goulding",
    "subject": "I've got Starry Eyes, lulz",
    "sent": "2013-09-21T19:45:00Z"
 },{
    "from": "Michael Stipe",
    "subject": "Everybody hurts, sometimes.",
    "sent": "2013-09-12T11:38:30Z"
 },{
    "from": "Jeremy Clarkson",
    "subject": "Think I've found the best car... In the world",
    "sent": "2013-09-03T13:15:11Z"
 }];

 });


 //$scope.shows does not get the data from window.myShows
 $scope.shows = window.myShows;

 // -- Native navigation
 steroids.view.navigationBar.show("Show index");

 });