Hide Div after showing 5sec JavaScript

What I want to achieve:

1. Hide Form Area after button click (DONE)
2. Show submit confirmation message on button click (DONE)
3. Hide Show submit confirmation message after showing it for 5 seconds
4. Show form area again

I'm stuck on point 3 & 4 and would appreciate any hints. I have tried the set time out function but without luck.I must be doing something wrong.

function hideDiv() {
               document.getElementById('FormArea').style.display = "none";
              }

function showDiv() {
              document.getElementById('submitarea').style.display = "block";
         }


setTimeout(function() {
    $('#submitarea').fadeOut('fast');
}, 1000); // <-- time in milliseconds