title: Declaring variables without var keyword
body: <p>At w3schools there is written:</p>
  
  <blockquote>
    <p>If you declare a variable, without using "var", the variable always becomes GLOBAL.</p>
  </blockquote>
  
  <p>Is it useful to declare global variable inside the function? I can imagine to declare some global variables in some event handler, but what is it good for? Better usage of RAM?</p>