An extrenal file Json

[mermi]

i am tring to import the name of my extrenal Json file by the url so i have change the script of the Radial Graph i need your help to say to me where is the error please
var labelType, useGradients, nativeTextSupport, animate;

(function() {
var ua = navigator.userAgent,
iStuff = ua.match(/iPhone/i) || ua.match(/iPad/i),
typeOfCanvas = typeof HTMLCanvasElement,
nativeCanvasSupport = (typeOfCanvas == 'object' || typeOfCanvas == 'function'),
textSupport = nativeCanvasSupport
&& (typeof document.createElement('canvas').getContext('2d').fillText == 'function');
//I'm setting this based on the fact that ExCanvas provides text support for IE
//and that as of today iPhone/iPad current text support is lame
labelType = (!nativeCanvasSupport || (textSupport && !iStuff))? 'Native' : 'HTML';
nativeTextSupport = labelType == 'Native';
useGradients = nativeCanvasSupport;
animate = !(iStuff || !nativeCanvasSupport);
})();

var Log = {
elem: false,
write: function(text){
if (!this.elem)
this.elem = document.getElementById('log');
this.elem.innerHTML = text;
this.elem.style.left = (500 - this.elem.offsetWidth / 2) + 'px';
}
};

function init(){
var pathArray = window.location.search.split( '?' );
var ref=pathArray[1];
var key = ref[4]+ref[5];
var json = $.getJSON("Data/"+key+".json", function(json) {
// console.log(json);
// data is a JavaScript object now. Handle it as such

console.log(json);
//init RGraph
var rgraph = new $jit.RGraph({
//Where to append the visualization
injectInto: 'infovis',
//Optional: create a background canvas that plots
//concentric circles.
//parent box title heights

    background: {
      CanvasStyles: {
        strokeStyle: '#000'
      }
    },
    //Add navigation capabilities:
    //zooming by scrolling and panning.
    Navigation: {
     enable: true,  
     panning: true,  
     zooming: 10
    },
    //Set Node and Edge styles.
    Node: {
        color: '#0000cc'
    },

    Edge: {
      color: '#CCC',
      lineWidth:1.5
    },

    onBeforeCompute: function(node){
        Log.write("centering " + node.name + "...");
        //Add the relation list in the right column.
        //This list is taken from the data property of each JSON node.
        $jit.id('inner-details').innerHTML = node.data.relation;
    },

  //Add the name of the node in the correponding label  
//and a click handler to move the graph.  
//This method is called once, on label creation.  
onCreateLabel: function(domElement, node){  
    domElement.innerHTML = node.name;  
    domElement.onclick = function(){  
        rgraph.onClick(node.id, {  
            onComplete: function() {  
                Log.write("done");  
            }  
        });  
    };  
},
 titleHeight: 15,
//Enable tips
Tips: {
  enable: true,
  //add positioning offsets
  offsetX: 20,
  offsetY: 20,
  //implement the onShow method to
  //add content to the tooltip when a node
  //is hovered
  onShow: function(tip, node) {
    var html = "<div class=\"tip-title\"> salutation:" + node.salutation 
      + "</div><div class=\"tip-text\">"+"<br><div class=\"tip-title\"> Name:" +node.name+"</div><div class=\"tip-text\">"

+"
<div class="tip-title"> Aspect:" +node.aspect+"<div class="tip-text">";

    tip.innerHTML =  html; 
  }  
},

    //Change some label dom properties.
    //This method is called each time a label is plotted.
    onPlaceLabel: function(domElement, node){
        var style = domElement.style;
        style.display = '';
        style.cursor = 'pointer';

        if (node._depth <= 1) {
            style.fontSize = "0.8em";
            style.color = "#494949";

        } else if(node._depth === 2){
            style.fontSize = "0.7em";
            style.color = "#ccc";

        } else {
            style.display = 'none';
        }

        var left = parseInt(style.left);
        var w = domElement.offsetWidth;
        style.left = (left - w / 2) + 'px';
    }
});
//load JSON data
rgraph.loadJSON(json);
//trigger small animation
rgraph.graph.eachNode(function(n) {
  var pos = n.getPos();
  pos.setc(-150, -150);
});
rgraph.compute('end');
rgraph.fx.animate({
  modes:['polar'],
  duration: 2000
});
//end

//append information about the root relations in the right column
//$jit.id('inner-details').innerHTML = rgraph.graph.getNode(rgraph.root).data.relation;

});
}