js刷新后记忆之前的值解决办法

js刷新后记忆之前的值
问题是这样的：
有个文本框之前是有默认值，但是如果用户一输入值那么刷新后文本框里的值还是用户输入的值。
麻烦各位帮忙用JS写一下。或提供一下思路也行。谢谢各位大侠了。

[解决办法]
用cookie吧

JScript code

function SetCookie(name,value) {    var key='';    var Days = 2;    var exp = new Date();    var domain = "";    exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);    if (key == null || key == "") {        document.cookie = name + "=" + encodeURI(value) + ";expires=" + exp.toGMTString() + ";path=/;domain=" + domain + ";";    }    else {        var nameValue = GetCookie(name);        if (nameValue == "") {            document.cookie = name + "=" + key + "=" + encodeURI(value) + ";expires=" + exp.toGMTString() + ";path=/;domain=" + domain + ";";        }        else {            var keyValue = getCookie(name, key);            if (keyValue != "") {                nameValue = nameValue.replace(key + "=" + keyValue, key + "=" + encodeURI(value));                document.cookie = name + "=" + nameValue + ";expires=" + exp.toGMTString() + ";path=/;domain=" + domain + ";";            }            else {                document.cookie = name + "=" + nameValue + "&" + key + "=" + encodeURI(value) + ";expires=" + exp.toGMTString() + ";path=/;" + domain + ";";            }        }    }}function GetCookie(name) {    var nameValue = "";    var key="";    var arr, reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");    if (arr = document.cookie.match(reg)) {        nameValue = decodeURI(arr[2]);    }    if (key != null && key != "") {        reg = new RegExp("(^| |&)" + key + "=([^(;|&|=)]*)(&|$)");        if (arr = nameValue.match(reg)) {            return decodeURI(arr[2]);        }        else return "";    }    else {        return nameValue;    }}
[解决办法]
JScript code
//保存用户条件var key = "<%=key %>";var stardate = "<%=stardate %>";var dataend = "<%=dataend %>";if (document.getElementById("serchinput").value == "") {    document.getElementById("serchinput").value = key;}if (document.getElementById("datastart").value == "") {    document.getElementById("datastart").value = stardate;}if (document.getElementById("dataend").value == "") {    document.getElementById("dataend").value = dataend;}        </script>