Executing JavaScript after X seconds

setTimeout will help you to execute any JavaScript code based on the time you set.

Syntax

setTimeout(code, millisec, lang)

Usage,

setTimeout("function1()", 1000);

For more details, see http://www.w3schools.com/jsref/met_win_settimeout.asp

onclick = "setTimeout(function() { document.getElementById('div1').style.display='none';document.getElementById('div2').style.display='none'}, 1000)"

Change 1000 to the number of milliseconds you want to delay.

I believe you are looking for the setTimeout function.

To make your code a little neater, define a separate function for onclick in a <script> block:

function myClick() {
  setTimeout(
    function() {
      document.getElementById('div1').style.display='none';
      document.getElementById('div2').style.display='none';
    }, 5000);
}

then call your function from onclick

onclick="myClick();"