react template

HTML

<script src="http://fb.me/react-js-fiddle-integration.js"></script>

JavaScript 1.7

/**
 * @jsx React.DOM
 */

var MyTextBox = React.createClass({
  getInitialState: function() {
    return {
      value: 'EMPTY'
    };
  },

  render: function() {
    return (
      <input 
        type="text"
        value={this.state.value}
        onKeyDown={this._onKeyDown}
      />
    );
  },

  _onKeyDown: function(e) {
    if (e.keyCode === 49) {
     this.setState({
       value: 'TEXT FOR 11111'
     });
    } else if (e.keyCode === 50) {
     this.setState({
       value: 'TEXT FOR 22222'
     });
    } else {
      return;
    }
  }
});

var renderComponent = function() {
  React.renderComponent(
    <div>
      <h1>Input '1' or '2'</h1> 
      <MyTextBox />
    </div>,
    document.body
  );
};

renderComponent();