打开浏览器只弹出一次的Javascript代码

tzlink

<script language="JavaScript">  
function openwin()   
{  
window.open("http://www.master8.net")  
}   
function get_cookie(Name)   
{var search = Name + "="   
var returnvalue = "";   
if (document.cookie.length > 0) {   
offset = document.cookie.indexOf(search)   
if (offset != -1) {   
offset += search.length   
end = document.cookie.indexOf(";", offset);   
if (end == -1)   
end = document.cookie.length;   
returnvalue=unescape(document.cookie.substring(offset,end))   
}   
}   
return returnvalue;   
}   
function loadpage(){   
if (get_cookie('opened')==''){   
openwin()   
document.cookie="opened=yes"   
}   
}  
loadpage()  
</script>