How to convert json file obtaining from source-API into xml file?

Example json: 

============

{"menu": {  
  "id": "file",  
  "value": "File",  
  "popup": {  
    "menuitem": m  
      {"value": "New", "onclick":"CreateDoc()"},  
      {"value": "Open", "onclick": "OpenDoc()"},  
      {"value": "Save", "onclick": "SaveDoc()"}  
    ]  
  }  
}}