【例4-1】网页中文字上下滚动循环显示。
<html>
<head>
<title>文字上下滚动循环显示</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script language=JavaScript>
var messages=new Array()
messages\[0\]="<font color=#8000FF>欢迎使用本书学习</font></a>"
messages\[1\]="<font color=#FB2500>这里有织网梦工厂</font></a>"
messages\[2\]="<font color=#FF0066F>是网页初学者的最佳选择</font></a>"
messages\[3\]="<font color=#000000>这里有…………有精彩的内容等着你</font></a>"
var scrollerwidth=320
var scrollerheight=100
var scrollerbgcolor=′#FFFFFF′
if (messages.length>1)
i=2
else
i=0
function move1(whichlayer){
tlayer=eval(whichlayer)
if (tlayer.top>0&&tlayer.top<=5){
tlayer.top=0
setTimeout("move1(tlayer)",3000)
setTimeout("move2(document.main.document.second)",3000)
return}
if (tlayer.top>=tlayer.document.height*-1){
tlayer.top-=5
setTimeout("move1(tlayer)",100)}
else{
tlayer.top=scrollerheight
tlayer.document.write(messages\[i\])
tlayer.document.close()
if (i==messages.length-1)
i=0
else
i++}}
function move2(whichlayer){
tlayer2=eval(whichlayer)
if (tlayer2.top>0&&tlayer2.top<=5){
tlayer2.top=0
setTimeout("move2(tlayer2)",3000)
setTimeout("move1(document.main.document.first)",3000)
return}
if (tlayer2.top>=tlayer2.document.height*-1){
tlayer2.top-=5
setTimeout("move2(tlayer2)",100)}
else{
tlayer2.top=scrollerheight
tlayer2.document.write(messages\[i\])
tlayer2.document.close()
if (i==messages.length-1)
i=0
else
i++}}
function move3(whichdiv){
tdiv=eval(whichdiv)
if (tdiv.style.pixelTop>0&&tdiv.style.pixelTop<=5){
tdiv.style.pixelTop=0
setTimeout("move3(tdiv)",3000)
setTimeout("move4(second2)",3000)
return}
if (tdiv.style.pixelTop>=tdiv.offsetHeight*-1){
tdiv.style.pixelTop-=5
setTimeout("move3(tdiv)",100)}
else{
tdiv.style.pixelTop=scrollerheight
tdiv.innerHTML=messages\[i\]
if (i==messages.length-1)
i=0
else
i++}}
function move4(whichdiv){
tdiv2=eval(whichdiv)
if (tdiv2.style.pixelTop>0&&tdiv2.style.pixelTop<=5){
tdiv2.style.pixelTop=0
setTimeout("move4(tdiv2)",3000)
setTimeout("move3(first2)",3000)
return}
if (tdiv2.style.pixelTop>=tdiv2.offsetHeight*-1){
tdiv2.style.pixelTop-=5
setTimeout("move4(second2)",100)}
else{
tdiv2.style.pixelTop=scrollerheight
tdiv2.innerHTML=messages\[i\]
if (i==messages.length-1)
i=0
else
i++}}
function startscroll(){
if (document.all){
move3(first2)
second2.style.top=scrollerheight}
else if (document.layers){
move1(document.main.document.first)
document.main.document.second.top=scrollerheight+5
document.main.document.second.visibility='show'}}
window.onload=startscroll
</script>
<ilayer id="main" width=&{scrollerwidth}; height=&{scrollerheight};
bgcolor=&{scrollerbgcolor};>
<layer id="first" left=0 top=1 width=&{scrollerwidth};>
<script language="JavaScript1.2">
if (document.layers)
document.write(messages\[0\])
</script>
</layer>
<layer id="second" left=0 top=0 width=&{scrollerwidth}; visibility=hide>
<script language="JavaScript1.2">
if (document.layers)
document.write(messages\[1\])
</script>
</layer>
</ilayer>
<script language="JavaScript1.2">
if (document.all){
document.writeln('<span id="main2" style="position:relative;width:'+scrollerwidth+';height:'+scrollerheight+';overflow:hiden;background-color:'+scrollerbgcolor+'">')
document.writeln('<div style="position:absolute;width:'+scrollerwidth+';height:'+scrollerheight+';clip:rect(0 '+scrollerwidth+' '+scrollerheight+' 0);left:0;top:0">')
document.writeln('<divid="first2"style="position:absolute;width:'+scrollerwidth+';left:0;top:1;">')
document.write(messages\[0\])
document.writeln('</div>')
document.writeln('<divid="second2"style="position:absolute;width:'+scrollerwidth+';left:0;top:0">')
document.write(messages\[1\])
document.writeln('</div>')
document.writeln('</div>')
document.writeln('</span>')
}
</script>
</head>
<body bgcolor="#FFFFFF" text="#000000">
</body>
</html>