Merge pull request facebook#2076 from whatasunnyday/master

Add example to if else in JSX.

Author: zpao

docs/tips/03-if-else-in-JSX.md

@@ -39,4 +39,25 @@ That's not valid JS. You probably want to make use of a ternary expression:
 React.renderComponent(<div id={condition ? 'msg' : ''}>Hello World!</div>, mountNode);
 ```
 
+If a ternary expression isn't robust enough, you can use `if` statements to determine which 
+components should be used.
+
+```js
+/** @jsx React.DOM */
+
+var loginButton;
+if (loggedIn) { 
+  loginButton = <LogoutButton />; 
+} else { 
+  loginButton = <LoginButton />; 
+}
+
+return (
+  <nav>
+    <Home />
+    {loginButton}
+  </nav>
+)
+```
+
 Try using it today with the [JSX compiler](/react/jsx-compiler.html).