title: a hover button in react.js
body: <p>i would like to ask how to make a button but when the mouse is on the button (hover),the new button is displayed above the previous button... and it's in react.js.. thx</p>
  
  <p>this is the way of my code..</p>
  
  <pre><code>var Category = React.createClass({displayName: 'Category',
    render: function () {
        return (
          React.createElement("div", {className: "row"}, 
          React.createElement("button", null, "Search",   {OnMouseEnter://I have no idea until here})
        )
      );
    }
  });
  
  React.render(React.createElement(Category), contain);
  </code></pre>