var Test = React.createClass({

      getInitialState: function() {
        return {
          value: "hallo"
        };
      },

      render: function() {
          return ( < form >
            < div >
            Onchange: < input type = "text"
            value = {
              this.state.value
            }
            onChange = {
              this.handleChange
            }
            /><br/ >
            Onblur: < input type = "text"
            value = {
              this.state.value
            }
            onBlur = {
              this.handleChange
            }
            />
      </div >
            < /form>
    );
  },
  handleChange: function(e){
      this.setState({value: e.target.value});
  }
});

React.renderComponent(<Test/ > , document.body);

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.12.2/react-with-addons.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.12.2/JSXTransformer.js"></script>