如果你用了jQuery库,参考楼上的,否则用下面的代码:
function bj(){var divNodes = document.getElementsByTagName("div")
for(var i=0,j=divNodes.lengthi<ji++){
var divObj = divNodes[i]
if(divObj.className == "caa" || divObj.className == "cab") {
divObj.style.background = "url(xx.jpg) no-repeat fixed left top"
}
}
}