Untitled

<p>CLICK TO CHANGE BACKGROUND COLOUR FOR MORE PLEASENT VIEWING.</p>


<button onclick="myFunction()">Try it</button>

<script>

window.onclick = myFunction;


function myFunction() {

  document.getElementsByTagName("BODY")[0].style.backgroundColor = "white";

}

</script>


</body>

</html>
<html>

<head>

<script>

function setCookie(cname,cvalue,exdays) {

  var d = new Date();

  d.setTime(d.getTime() + (exdays*24*60*60*1000));

  var expires = "expires=" + d.toGMTString();

  document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";

}


function getCookie(cname) {

  var name = cname + "=";

  var decodedCookie = decodeURIComponent(document.cookie);

  var ca = decodedCookie.split(';');

  for(var i = 0; i < ca.length; i++) {

    var c = ca[i];

    while (c.charAt(0) == ' ') {

      c = c.substring(1);

    }

    if (c.indexOf(name) == 0) {

      return c.substring(name.length, c.length);

    }

  }

  return "";

}


function checkCookie() {

  var user=getCookie("username");

  if (user != "") {

    alert("Welcome again " + user);

  } else {

     user = prompt("Please enter your name:","");

     if (user != "" && user != null) {

       setCookie("username", user, 30);

     }

  }

}

</script>

</head>


<body onload="checkCookie()"></body>