请问有没办法让网页浮标滚动到某个高度时就消失呢？

Question

网页浮标指的是什么呢？
如果是浮动的层，可以判断它的style.top值
if(parseInt(oDiv.style.top) > 300 )
   oDiv.style.visibility='hidden';

Answer 1

是这种：<script>
var imgheight
document.ns = navigator.appName == "Netscape"
window.screen.width>800 ? imgheight=100:imgheight=100 function myload()
{
if (navigator.appName == "Netscape")
{document.myitcom.pageY=pageYOffset+window.innerHeight-imgheight;
document.myitcom.pageX=+window.innerWidth-120;
mymove();
}
else
{
myitcom.style.top=document.body.scrollTop+document.body.offsetHeight-imgheight;
myitcom.style.left=document.body.offsetWidth-120;
mymove();
}
}function mymove()
 {
 if(document.ns)
 {
 document.myitcom.top=pageYOffset+window.innerHeight-imgheight;
 document.myitcom.left=pageXOffset+window.innerWidth-120;
 setTimeout("mymove();",50)
 }
 else
 {
 myitcom.style.top=document.body.scrollTop+document.body.offsetHeight-imgheight;
 myitcom.style.left=document.body.scrollLeft+document.body.offsetWidth-100;
 setTimeout("mymove();",50)
 }
 }function MM_reloadPage(init) {  //reloads the window if Nav4 resized
  if (init==true) with (navigator) {if ((appName=="Netscape")&&(parseInt(appVersion)==4)) {
    document.MM_pgW=innerWidth; document.MM_pgH=innerHeight; onresize=MM_reloadPage; }}
  else if (innerWidth!=document.MM_pgW || innerHeight!=document.MM_pgH) location.reload();
}
MM_reloadPage(true)
if (navigator.appName == "Netscape")
{document.write("<layer id=myitcom top=300 width=80 height=80><a href='http://www.123.com/' target=_blank><img src='8080.gif' width='80' height='80' border='0' vspace='0'></A></layer>");
myload()}
else
{
document.write("<div id=myitcom style='position: absolute;width:80;top:0;left:578;visibility: visible;z-index: 1'><a href='http://www.123.com/' target=_blank><img src='8080.gif' width='80' height='80' border='0' vspace='0'></A></div>");
myload()
}
</script>