button按钮背景图及隐藏value的值

怎样写button按钮背景图才能让IE6显示？

.goods_buy_info .goods_buy_but .goods_buy_but {
	background: url(../images/goods20110309_25.gif);
	background-repeat: no-repeat;
	background-position: left top;
	border:0px;
}

注意点就在background: url(../images/goods20110309_25.gif);
千万不能写成background-img: url(../images/goods20110309_25.gif);
怎样写css才能使button隐藏value值呢?

.goods_buy_info .goods_buy_but .goods_buy_but {
	float:left;/*或者float:left|right*/
	width:138px;
	height:39px;
	overflow:hidden;
	text-indent:-9999px;
	text-transform:capitalize;
	border:0px;
}

注意点
1.float:left;/*或者float:left|right*/
2.高度与宽度
3.text-indent一定要足够大
4.最好加上text-transform:capitalize;
下面付上按钮代码：

<style>
.goods_buy_but {
	float:left;/*或者float:left|right*/
	width:138px;
	height:39px;
	overflow:hidden;
	text-indent:-9999px;
	text-transform:capitalize;
	background: url(../images/goods20110309_25.gif);
	background-repeat: no-repeat;
	background-position: left top;
	border:0px;
}
</style>
<input class="goods_buy_but" name="" type="submit" value="提交"/>