<img src="javascript:bt_1.style.background='url(图片地址)';bt_2.style.
background='url(图片地址)';bt_3.style.background='url(图片地址)';bt_4.style.
background='url(图片地址)';bt_5.style.background='url(图片地址)';bt_6.style.
background='url(图片地址)';bt_7.style.background='url(图片地址)';bt_8.style.
background='url(图片地址)';"></img>

下面这个代码可以使QQ空间导航条背景透明!!!

<img src="javascript:bt_1.style.background='url()';bt_2.style.background=
'url()';bt_3.style.background='url()';bt_4.style.background='url()';bt_
5.style.background='url()';bt_6.style.background='url()';bt_7.style.
background='url()';bt_8.style.background='url()';"></img>