css 单图片按钮实例(css 图片变换)

<a id="theLink"></a>

#theLink{
display:block;/*因为标签a是内链元素，所以利用这句话将内链元素转化成块状元素，后面的width和height才起作用*/
width:120px;
height:41px;
margin:0 auto;
background:url(../images/normal.gif) no-repeat;
}
#theLink:hover{background:url(../images/press.gif) no-repeat;}

<a id="buttonBlock"></a>

#theLink{
display:block;
width:120px;
height:41px;
margin:0 auto;
background:url(../images/buttonBG.gif) no-repeat;
}
#theLink:hover{ background:url(../images/buttonBG.gif) no-repeat 0 -41px;}