Untitled

file=states.json
{
  identifier:"abbreviation",
  label: "name",
  items: [
        {name:"India", label:"India",abbreviation:"IND"},
        {name:"USA", label:"USA",abbreviation:"USA"},
        {name:"UK", label:"UK",abbreviation:"UK"},
        {name:"Germany", label:"Germany",abbreviation:"GER"},
         ]
}

--------In the form which uses this json file--------------------
<div dojoType="dojo.data.ItemFileReadStore" jsId="stateStore" url="states.json">
<input dojoType="dijit.form.ComboBox"  value="Select Country" store="stateStore" searchAttr="abbreviation" name="country" id="country" onChange="populateCity"/>