用js实现跑马灯抽奖效果

<table>
<tr>
<td><img id="img1" src="img/1.jpg"></td>
<td><img id="img2" src="img/2.jpg"></td>
<td><img id="img3" src="img/3.jpg"></td>
</tr>
<tr>
<td><img id="img8" src="img/4.jpg"></td>
<td id="control" onclick="start()" style="text-align: center;font-size: 72px;color:red;background-color: yellow;opacity:1;">
START
</td>
<td><img id="img4" src="img/5.jpg"></td>
</tr>
<tr>
<td><img id="img7" src="img/6.jpg"></td>
<td><img id="img6" src="img/7.jpg"></td>
<td><img id="img5" src="img/8.jpg"></td>
</tr>
</table>

/*以上是body部分，下面为js实现部分*/

<pre name="code" class="javascript">var seed = null;function start(){var imgCount = 1;var status = $("#control");if( status.html().trim() == "START" ){status.html("END");seed = setInterval(function(){if( imgCount > 8 ){imgCount = 1;}$("[id^=img]").each(function(index, value){var imgIndex = $(value).attr("id").substring(3,4);if(imgIndex == imgCount){$("#img" + imgIndex).css("opacity", 1);} else {$("#img" + imgIndex).css("opacity", 0.5);}});++imgCount;});} else {status.html("START");clearInterval( seed );}}