Javascript Sample (Back ground color change)

  var sw = true;
  var no = 0;
  function timer() {
    if (sw) { no++; } else { no--; }
    if(no > 14 || no < 1) {
      sw = ((sw) ? false : true);
    }
    var hex = no.toString(16).toUpperCase();
    document.bgColor = '#FFFF' + hex + hex;
    document.getElementById('txtno').value = 'FFFF' + hex + hex;
    window.setTimeout('timer()', 500);
  }
  window.onload = function () {
    window.setTimeout('timer()', 50);
  }