title: Show Button to slide down the header after slide
body: <p>i am creating my website and i have a problem. 
  On top of my page there is my header and in it my nav 
  When i scroll down the page and the header isn't in the visible window i want to slide down (from top) another DIV (then fixed to the top and always visible) with a button. When the User clicks on the button must my header slide down.</p>
  
  <p>If the user scrolls back to the top of my page an the header comes in to the visible window my fixed DIV with the buttons must disapear. </p>
  
  <p>I hope you understand what i mean with my very bad english und hope you can help me. </p>