function getOperators(country) {
    
    var url = "/ringtone/getoperators";
        
    dojo.xhrPost( {
        url: url,
        postData: "country=" + country,
        handleAs: "text",
        load: function(response) {
            dojo.byId('operatorSelect').innerHTML = response;
            dojo.byId('subscriber').disabled = true;
            prefixIndex = dojo.byId('prefix').selectedIndex;
            dojo.byId('prefix').options[prefixIndex].text = '-';
            dojo.byId('prefix').disabled = true;
        }
    } );
}

function getPrefixes(operator) {
 
    var url = "/ringtone/getprefixes";
        
    dojo.xhrPost( {
        url: url,
        postData: "operator=" + operator,
        handleAs: "text",
        load: function(response) {
            dojo.byId('prefixSelect').innerHTML = response;
        }
    } );
}

function validateForm() {
    
    var subscriber = dojo.byId('subscriber');
    
    if (!dojo.byId('country').value || !dojo.byId('operator').value 
        || isNaN(subscriber.value) || subscriber.value.length < 6 || !dojo.byId('agb').checked)
    {
        dijit.byId('gettone').setAttribute('disabled', true);
    }
    else
    {
        dijit.byId('gettone').setAttribute('disabled', false);
    }
}