cookie
<html> <head> <script type="text/javascript"> function getCookie(c_name) { document.write("my cookie:" + document.cookie) if (document.cookie.length > 0) { c_start=document.cookie.indexOf(c_name + "=") if (c_start!=-1) { c_start=c_start + c_name.length + 1 c_end=document.cookie.indexOf(";", c_start) if (c_end == -1) { c_end=document.cookie.length } return unescape(document.cookie.substring(c_start,c_end)) } } return "" } function setCookie(c_name, value, expiredays) { var exdate = new Date() exdate.setDate(exdate.getDate() + expiredays) document.cookie= c_name+ "=" + escape(value) + ((expiredays==null) ? "" : "; expires=" + exdate.toGMTString()) } function checkCookie() { document.cookie = "ab=123"; username=getCookie(‘username‘) if (username!=null && username!="") { alert(‘Welcome again ‘+username+‘!‘) } else { username=prompt(‘Please enter your name:‘,"") if (username!=null && username!="") { setCookie(‘username‘, username, 365) } } } </script> </head> <body onLoad="checkCookie()"> </body> </html>