你的i定义错地方了
<HTML>
<HEAD>
<TITLE>Thank you</TITLE>
<script>
var i=1;
function effect()
{
var m=eval("level_"+i);
eval("level_"+i+".style.color='red'");
i+=1;
if(i>10) i=1;
setTimeout('effect()',1000);
}
</script>
</HEAD><BODY onload="effect()">
<script>
for(var j=1;j<=10;j++)
document.write("<h3 id=level_"+j+">nothing can baffles me!!</h3>");
</script>
</BODY>
<HTML>
<HEAD>
<TITLE>Thank you</TITLE>
<script>
var i=1;
function effect()
{
var m=eval("level_"+i);
eval("level_"+i+".style.color='red'");
i+=1;
if(i>10) i=1;
setTimeout('effect()',1000);
}
</script>
</HEAD><BODY onload="effect()">
<script>
for(var j=1;j<=10;j++)
document.write("<h3 id=level_"+j+">nothing can baffles me!!</h3>");
</script>
</BODY>
<HEAD>
<TITLE>Thank you</TITLE>
<script>
function effect(i)
{
if (i == null ) i=1;
var m=eval("level_"+i);
m.style.color="red";
if(i++ < 10) setTimeout("effect("+i+")",1000);
}
</script>
</HEAD><BODY onload="effect()">
<script>
for(var j=1;j<=10;j++)
document.write("<h3 id=level_"+j+">nothing can baffles me!!</h3>");
</script>
</BODY>m是你自己定义的局部变量,不能通过document.all.m来访问的。
<HTML>
<HEAD>
<TITLE>Thank you</TITLE>
<script>
var i=1;
function effect()
{
eval("level_"+i+".style.color='red'");
if (i!=1)
eval("level_"+(i-1)+".style.color='black'");
else
eval("level_"+10+".style.color='black'")
i+=1;
if(i>10) i=1;
setTimeout('effect()',1000);
}
</script>
</HEAD><BODY onload="effect()">
<script>
for(var j=1;j<=10;j++)
document.write("<h3 id=level_"+j+">nothing can baffles me!!</h3>");
</script>
</BODY>