鼠标放到链接上出现一个说明框，里面有滚动的文字说明

< a href = " http://www.helpor.net "  target = " _blank "  onMouseOver = " helpor_net_show(this,event,'看到了吧？') "  onMouseOut = " helpor_net_hide() " > 把鼠标放上来试试 </ a >
< div id = " tooltip2 "  style = " position:absolute;visibility:hidden;clip:rect(0 150 50 0);width:150px;background-color:seashell " >
< layer name = " nstip "  width = " 1000px "  bgColor = " seashell " ></ layer >
</ div >
< SCRIPT language = " JavaScript " >
<!--
if  ( ! document.layers &&! document.all)
event = " test "
function  helpor_net_show(current,e,text) ... {

if (document.all&&document.readyState=="complete")...{
document.all.tooltip2.innerHTML='<marquee style="border:1px solid #3399ff">'+text+'</marquee>'
document.all.tooltip2.style.pixelLeft=event.clientX+document.body.scrollLeft+10
document.all.tooltip2.style.pixelTop=event.clientY+document.body.scrollTop+10
document.all.tooltip2.style.visibility="visible"
}

else if (document.layers)...{
document.tooltip2.document.nstip.document.write('<b>'+text+'</b>')
document.tooltip2.document.nstip.document.close()
document.tooltip2.document.nstip.left=0
currentscroll=setInterval("scrolltip()",100)
document.tooltip2.left=e.pageX+10
document.tooltip2.top=e.pageY+10
document.tooltip2.visibility="show"
}
}
function  helpor_net_hide() ... {
if (document.all)
document.all.tooltip2.style.visibility="hidden"
else if (document.layers)...{
clearInterval(currentscroll)
document.tooltip2.visibility="hidden"
}
}

function  scrolltip() ... {
if (document.tooltip2.document.nstip.left>=-document.tooltip2.document.nstip.document.width)
document.tooltip2.document.nstip.left-=5
else
document.tooltip2.document.nstip.left=150
}
// -->
</ SCRIPT >