代码如下：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html> <head> <SCRIPT LANGUAGE="javascript"> <!-- function open () {return true;} //--> </SCRIPT> <title>随机选取字符串并改变颜色_www.jb200.com</title> </head> <BODY bgcolor=green text="white" bgcolor="green" link="yellow" vlink="yellow" alink="red"> <font color="yellow"> <SCRIPT LANGUAGE="JavaScript"> var speed = 20; var fulltext; if(navigator.appName == "Netscape") document.write('<layer id="wds"></layer><br>'); if (navigator.appVersion.indexOf("MSIE") != -1) document.write('<span id="wds"></span><br>'); function livetext() { fulltext="this is an example of random effect text" var whichchar=Math.round((Math.random()*fulltext.length)) switch(whichchar){ case 0: fulltext = '<font color="red">' + fulltext.substring(0,1) + '</font>' + fulltext.substring (1,fulltext.length); break; case fulltext.length: fulltext = fulltext.substring(0,fulltext.length-1) + '<font color="red">' + fulltext.substring (fulltext.length-1,fulltext.length) + '</font>'; break; default: fulltext = fulltext.substring(0,whichchar) + '<font color="violet">' + fulltext.substring(whichchar,whichchar+1) + '</font>' + fulltext.substring(whichchar+1,fulltext.length); break; } if(navigator.appName == "Netscape") { size = "<font point-size='25pt'>"; document.wds.document.write(size+'<center>' + fulltext + '</center></font>'); document.wds.document.close(); } if (navigator.appVersion.indexOf("MSIE") != -1){ wds.innerHTML = '<center>' + fulltext + '</center><p>'; wds.style.fontSize='25px' } setTimeout("livetext()",speed); } livetext() </script> </font> </body> </html>