JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cloud.github.com/downloads/SteveSanderson/knockout/knockout-2.0.0.debug.js"></script>
<div>
    <input type="text" data-bind="value: InputValue, event: { keypress: RunSomethingKey }" />
    <input type="button" value="test" data-bind="click: RunSomething" />
    <br/>
    <span data-bind="text: InputValue"></span>
</div>

JavaScript

var ViewModel = function() {
    var self = this;
    self.InputValue = ko.observable('');
    
    self.RunSomethingKey = function (viewModel, event) {
        if (event.keyCode == 13) {
            self.RunSomething(viewModel, event);
        }
        return true;
    }
    
    self.RunSomething = function(viewModel, event) {
        window.alert(viewModel.InputValue());
    }
}
    
ko.applyBindings(new ViewModel());