Update article.md

The old code doesn't work. Is this what you wanted to show?
2017-06-05 09:59:09 -04:00 · 2017-06-05 09:59:09 -04:00 · 8d150d44db
commit 8d150d44db
parent 168b273caa
1 changed files with 1 additions and 1 deletions
--- a/2-ui/1-document/01-browser-environment/article.md
+++ b/2-ui/1-document/01-browser-environment/article.md
@ -25,7 +25,7 @@ function sayHi() {
 }

 // global functions are accessible as properties of window
-alert(window.sayHi);
+window.sayHi();
 ```

 And here we use it as a browser window, to see the window height: