handleBlur: function () {

  this.setState({validating: true});

},

render: function () {

  return <div>

    ...

    <input

        type="password"

        placeholder="Password (confirm)"

        valueLink={this.linkState('password2')}

        onBlur={this.handleBlur}

     />

    ...

    {this.renderPasswordConfirmError()}

  </div>

},

renderPasswordConfirmError: function() {

  if (this.state.validating && this.state.password !== this.state.password2) {

    return (

      <div>

        <label className="error">Please enter the same password again.</label>

      </div>

    );

  }  

  return null;

},