通过函数和函数参数设置DIV的javascript背景图像

I have the following HTML:

我有以下HTML:

<div id="tab1" style="position:relative; background-image:url(buttons/off.png);
    <a href="/go.html?url=javascript:ChangeBackgroundImageOfTab('tab1', 'on');">
        <img id="DivBtn1" name="DivBtn1" src="buttons/text.png" >
    </a>
</div>
<div i