Knockoutjs.com - Hello World Example

http://knockoutjs.com/examples/helloWorld.html

HTML

<script src="http://knockoutjs.com/downloads/knockout-3.2.0.js"></script>
<script src="https://code.jquery.com/jquery-3.0.0.min.js&quot;   integrity=&quot;sha256-JmvOoLtYsmqlsWxa7mDSLMwa6dZ9rrIdtrrVYRnDRH0="></script>
EnableMe: <input id="myradio1" type="radio" data-bind='checked: enableMe'/><br/>
Enable status: <span data-bind='text: enableMe'></span>
<br/>
<button id="button1" onclick="clickme();">Click To Disable</button>

JavaScript

var ViewModel = function() {   
    
    this.enableMe = ko.observable(false);    
};
 
var myVM = new ViewModel();
 
ko.applyBindings(myVM); 

function clickme() {
   //Changing the checked state does not change VM
   document.getElementById("myradio1").checked = true;
   //Changing the VM works
   //myVM.name("Updated name");
   //myVM.enableMe(true);
   
   alert("Alert Message OnClick");
}