How to create the effect like this page?

Click "Reply by Email" of that page,

http://los开发者_C百科angeles.kijiji.com/rooms-roommates/el-monte/room-for-rent-el-monte-california-91732/?ad=785656

By using jQuery you can simply use the show() method:

$("button").click(function () {
  $("#mydiv").show("slow");
});

More info here: http://docs.jquery.com/Effects/show

In jQuery the effect closer to that page is slideDown:

$("button").click(function () {
  $("#mydiv").slideDown("slow");
});

With jQuery. See jQuery Effects/animate.

I believe MooTools is capable of doing this task. If not its not that hard to create that effect. Use setInterval to create an interval that repeats itself and resizes the box.

Simply jQuery

With one line of code you can do this.

www.jquery.com