A:
<script language="JavaScript">
text = "十万个为什么网站"; //显示的文字
color1 = "blue"; //文字的颜色
color2 = "red"; //转换的颜色
fontsize = "8"; //字体大小
speed = 200; //转换速度 (毫秒)
i = 0;
if (navigator.appName == "Netscape") {
document.write("<layer id=a visibility=show></layer><br><br><br>");
}
else {
document.write("<div id=a></div>");
}
function changeCharColor()
{if (navigator.appName == "Netscape") {
document.a.document.write("<center><font face=arial size =" + fontsize + "><font color=" + color1 + ">");
for (var j = 0; j < text.length; j++) {
if(j == i){document.a.document.write("<font face=arial color=" + color2 + ">" + text.charAt(i) + "</font>");}
else {document.a.document.write(text.charAt(j));}
}
document.a.document.write('</font></font></center>');
document.a.document.close();
}
if (navigator.appName == "Microsoft Internet Explorer") {
str = "<center><font face=arial size=" + fontsize + "><font color=" + color1 + ">";
for (var j = 0; j < text.length; j++) {
if( j == i) {
str += "<font face=arial color=" + color2 + ">" + text.charAt(i) + "</font>";
}
else {
str += text.charAt(j);
}
}
str += "</font></font></center>";
a.innerHTML = str;
}
(i == text.length) ? i=0 : i++;
}
setInterval("changeCharColor()", speed);
</script>