title: javascript alt key
body: <p>We are creating a web user interface that looks like a desktop window.
  Now we need to handle the <kbd>Alt</kbd> key. When <kbd>Alt</kbd> key is pressed the focus goes to the upper menu.</p>
  
  <p>In Javascript, how to get the event for <kbd>Alt</kbd> key when ONLY <kbd>Alt</kbd> key is pressed? I need to ensure that no other key was pressed at the same time.</p>
  
  <p>Thanks in advance.</p>