1<div id="contain">
2 <div class='wrap' id='wrap1'>
3 <div class='ball' id='ball1'></div>
4 </div>
5
6 <div class='wrap' id='wrap2'>
7 <div class='ball' id='ball2'></div>
8 </div>
9
10 <div class='wrap' id='wrap3'>
11 <div class='ball' id='ball3'></div>
12 </div>
13
14 <div class='wrap' id='wrap4'>
15 <div class='ball' id='ball4'></div>
16 </div>
17
18</div>