<script>
window.onload = function () {
var s_uname = ‘<% =Session["uname"] %>‘;
if (s_uname == "") {
window.location.href = "../Login.aspx";
}
}
</script>
js检测服务器端Seesion是否存在,布布扣,bubuko.com
原文：http://www.cnblogs.com/sijie/p/3916072.html