how to get the values of array in alert box

Question

i am trying to create the facebook app. i want to use alert box. i dont know how to print the array values in alert..

"data": [
    {
      "name": "a",
      "id": "585"
    },
    {
      "name": "b",
      "id": "6259"
    },
    {
      "name": "c",
      "id": "65209"
    }
]

In this I want to print a,585..