//其中default.htm默认已经存在
<script language="javascript" >
function intro(){
if((navigator.appVersion.indexOf("Mac")!=-1)&&
(navigator.userAgent.indexOf("MSIE")!=-1)&&
(parseInt(navigator.appVersion)=4)){
skip()
}else{
popup()
}
}
function skip(){
location.href="default.htm";
}
function popup(){
version=parseFloat(navigator.appVersion.substring(navigator.appVersion.indexOf('.')-1,
navigator.appVersion.length));
if(version>=4)
version=parseFloat(navigator.appVersion.substring(navigator.appVersion.indexOf('.')-1,
navigator.appVersion.length));
if(version>=4){
if(navigator.appName=="Netscape"){
Hello=window.open("default.htm","Hello","scrollbars");
Hello.focus();
}
if(navigator.appName=="Microsoft Internet Explorer"){
 window.open("default.htm","screen","fullscreen==yes");
 }
 else{
 location.href="default.htm";
 }
 }
 </script>