funciones – Data recovery in javascript

Result of the recovery of the result of the operation:

function mycallblack (json) {
var i = 1;
for (var j = 0; j <json.feed.entry[i].link.length; j ++) {
if (json.feed.entry[i].link[j].rel ==> alternative & # 39;) {
var postUrlblack = json.feed.entry[i].link[j].href;
return postUrlblack;
Pause;
}
}

}

var returnValue = mycallblack (json);
document.write (returnValue);

var num = Math.floor (Math.random () * 100); var mycallblack
var script = document.createElement (& # 39; script & # 39;);
script.src = "http://es.stackoverflow.com/feeds/posts/summary?start-index="+ num + & # 39; & max-results = 8 & alt = json-in-script & callback = mycallblack & # 39 ;; document.write (script.outerHTML);

The variable

Quote blocked

returnValue

No regresa ningĂșn valor. espero su ayuda