Select value binding in KO

Sample of binding a select options value to a ko.observable

HTML

<script src="http://ajax.aspnetcdn.com/ajax/knockout/knockout-2.2.1.js"></script>
  <select data-bind="options: produceList, optionsText:'productName', optionsCaption: 'Choose...', value: selectedItem"></select>

<hr/>
<span data-bind="text: selectedItem()"></span>

JavaScript

var myProduceModel = function(){
 var self = this;

    
    self.produceList = ko.observableArray([
        {productName: "Apples", productCode: "#FF0000"},
        {productName: "Oranges", productCode: "#FF9200"},
        {productName: "Grapes", productCode: "#652C90"},
        {productName: "Figs", productCode: "#67070D"}    
        ]);
        
    self.selectedItem = ko.observable();
    self.selectedField = ko.observable();
    
    self.selectedItem.subscribe(function(item){
        self.selectedField(item.productName);
        return item.productCode;
    });
};

    ko.applyBindings(new myProduceModel());