jsonCallback({
  "content": [
  {
    "name": "UK",
    "children": [
        {
          "name":"England",
          "children": [
              {"name":"Essex"},
              {"name":"Worcs"},
              {"name":"Berks"}
            ]
        },
        {
          "name":"Scotland",
          "children": [
              {"name":"Lanarkshire"}
            ]
        }
      ]
  },{
    "name":"USA",
    "children":[
        {
          "name":"Washington",
          "children":[
              {"name":"Seattle"},
              {"name":"Redmond"}
            ]
        }
      ]
  }]
});