让窗口仅弹出一次
?牐?<SCRIPT language="JavaScript">
?牐?<!--
?牐爁unction openpopup(){
?牐爓indow.open("welcome.htm","","width=300,height=300")??
?牐爙
?牐爁unction get_cookie(Name){?? ??
?牐爒ar search=Name + "="
?牐爒ar returnvalue = "";
?牐爄f(document.cookie.length > 0){?? ??
?牐爋ffset=document.cookie.indexOf(search)
?牐爄f(offset!= -1){// if cookie exists
?牐爋ffset +=search.length
?牐?//set index of beginning of value
?牐爀nd = document.cookie.indexOf(";",offset);?牔?
?牐?//set index of end of cookie value
?牐爄f(end == -1)??
?牐爀nd=document.cookie.length;
?牐爎eturnvalue=unescape(document.cookie.substring(offset,end))?牐?
?牐爙
?牐爙??
?牐爎eturn returnvalue;
?牐爙
?牐爁unction loadpopup?煟牓?
?牐爄f(get_cookie('popped')==''){?牓?
?牐爋penpopup()
?牐燿ocument.cookie="popped=yes"
?牐爙
?牐爙??
?牐?//-->
?牐?</SCRIPT>
?牐牭诙?:把<body>中内容改为:
?牐?<body bgcolor="#fef4d9" onunload="loadpopup()>