Jason Overview - Cascade Dropdown Using JSON

Javascript
Below i have specified sample of cascaded Dropdown using JSON.

function fnDrpChange()

{

try

{

var countries =

{

    "table" :

    [

        {"countryid": "0", "countryname": "Japan"},

        {"countryid": "1", "countryname": "India"},

        {"countryid": "2", "countryname": "Pakistan"},

        {"countryid": "3", "countryname": "Srilanka"}

    ]

};

var listItems ="";

for (var i = 0; i < countries.table.length; i++) {

    listItems += "<option value='" + countries.table[i].countryid + "'>" + countries.table[i].countryname + "</option>";

}

document.getElementById("ddlcountries").innerHTML =listItems;

}

catch(e)

{

alert(e);

}

}

function fnCountryChange(countryid)

{

try

{

var states =

{

    "table" :

    [

        {"countryid": "1", "stateid": "1", "statename": "TamilNadu"},

        {"countryid": "1", "stateid": "2", "statename": "Andra"},

        {"countryid": "1", "stateid": "3", "statename": "Kerala"}

    ]

};

var listItems ="";

for (var i = 0; i < states.table.length; i++) {

if(countryid == states.table[i].countryid)

{

    listItems += "<option value='" + states.table[i].stateid + "'>" + states.table[i].statename + "</option>";

}

}

document.getElementById("ddlstates").innerHTML =listItems;

}

catch(e)

{

alert(e);

}

}

Click Here to See Demo