JS获取地址栏并拼接參数

比方地址栏是这种：http://www.aa.com/detail.aspx?code=1&start=2014-12-01&end=2014-12-23&name=abc

要获取到“?

code=1&start=2014-12-01&end=2014-12-23&name=abc”，例如以下：

前台页面head标签内：

<script type="text/javascript">
    function GetQueryString(name) {
        var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)");
        var r = window.location.search.substr(1).match(reg);
        if (r != null) return unescape(r[2]); return null;
    }
    function GetUrlQueryString() {
        var query = '?';
        var code = escape(GetQueryString("code"));
        if (code != null && code.toString().length > 0) {
            query += 'code=' + code + '&';
        }
        var start = escape(GetQueryString("start"));
        if (start != null && start.toString().length > 0) {
            query += 'start=' + start + '&';
        }
        var end = escape(GetQueryString("end"));
        if (end != null && end.toString().length > 0) {
            query += 'end=' + end + '&';
        }
        var name = escape(GetQueryString("name"));
        if (name != null && name.toString().length > 0) {
            query += 'name=' + name;
        }
        return query;
    }
</script>

button：

<input type="button" value="导出" class="button1" onclick="javascript:window.open('ExportToExcel.aspx' + GetUrlQueryString());" />