Javascript实现"点按钮出随机背景色的"三个DIV

<!DOCTYPE html>
<html>
<head>
    <title>Random_Color-Transformation</title>
    <style type="text/css">
        .div1{
            height: 50px ;
            width: 320px;
            background-color: red;
            font-size: 0.5em;
            font-weight: bold;
            font-style: italic;
            text-decoration: underline;
        }
        .div2{
            height: 50px ;
            width: 320px;
            background-color: yellow;
            font-size: 1em;
            font-weight: bold;
            font-style: italic;
            text-decoration: underline;
        }
    </style>

    <style type="text/css">
        .div3{
            height: 50px ;
            width: 320px;
            background-color: green;
            font-size: 2em;
            font-weight: bolder;
            font-style: oblique;
        }
    </style>
</head>
<body>
    <div class = "div1" id="00">
        Some contents here!
    </div>
    <input type="button" value="00" onclick = "getBgColor(this);" />
    <div class = "div2" id="01">
        Some contents here!
    </div>
    <input type="button" value="01" onclick = "getBgColor(this);" />
    <div class = "div3" id="10">
        Some contents here!
    </div>
    <input type="button" value="10" onclick = "getBgColor(this);" />
</body>
<script type="text/javascript">
    function getBgColor(t){
        var myDiv = document.styleSheets[t.value.substring(0,1)].cssRules[t.value.substring(1,2)].style.backgroundColor;
        alert(myDiv);
        var a = Math.floor(255*Math.random()) + '';
        var b = Math.floor(255*Math.random()) + '';
        var c = Math.floor(255*Math.random()) + '';
        document.styleSheets[t.value.substring(0,1)].cssRules[t.value.substring(1,2)].style.backgroundColor = 'rgb(' + a + ',' + b + ',' + c + ')';

    }
</script>
</html>