var obj=document.getElementById("ad")
function floatAD() {
var L=T=0
var R= document.body.clientWidth-obj.offsetWidth
var B = document.body.clientHeight-obj.offsetHeight
obj.style.left = x + document.body.scrollLeft
obj.style.top = y + document.body.scrollTop
x = x + step*(xin?1:-1)
if (x < L) { xin = true; x = L}
if (x > R){ xin = false; x = R}
y = y + step*(yin?1:-1)
if (y < T) { yin = true; y = T }
if (y > B) { yin = false; y = B }
}谁能解释一下意思啊???
function floatAD() {
var L=T=0
var R= document.body.clientWidth-obj.offsetWidth
var B = document.body.clientHeight-obj.offsetHeight
obj.style.left = x + document.body.scrollLeft
obj.style.top = y + document.body.scrollTop
x = x + step*(xin?1:-1)
if (x < L) { xin = true; x = L}
if (x > R){ xin = false; x = R}
y = y + step*(yin?1:-1)
if (y < T) { yin = true; y = T }
if (y > B) { yin = false; y = B }
}谁能解释一下意思啊???
<script type="text/javascript">
var obj=document.getElementById("ad")
function floatAD() {
var L=T=0;//BODY区域左边框、上边框
var R= document.body.clientWidth-obj.offsetWidth;//BODY区域右边框(BODY宽-AD宽,为了不让AD的右边框移出BODY的右边框)
var B = document.body.clientHeight-obj.offsetHeight;//BODY区域的下边框(同上)
obj.style.left = x + document.body.scrollLeft;//x应该是当前x坐标,加上滚动条的滚动宽度,保证AD随滚动条而滚动
obj.style.top = y + document.body.scrollTop;//y应该是当前y坐标,加上滚动条的滚动高度,保证AD随滚动条而滚动
x = x + step*(xin?1:-1);//AD坐标改变,实现移动效果,xin为移动方向
if (x < L) { xin = true; x = L} //到达左边框时,向右移动
if (x > R){ xin = false; x = R} //同上
y = y + step*(yin?1:-1) //同上
if (y < T) { yin = true; y = T }//同上
if (y > B) { yin = false; y = B } //同上
}
</script>