IsClientScriptBlockRegistered超时？

if (LoginCheck.Logining(user, pass) == 1)
{
if (!IsClientScriptBlockRegistered("alertlogin1"))
{
RegisterClientScriptBlock("alertlogin1", "<script language='javascript'>alert('登陆成功');window.location.href= 'Admin_index.aspx';</script>");
}

}
else
{
if (!IsClientScriptBlockRegistered("alertlogin2"))
{
RegisterClientScriptBlock("alertlogin2", "<script language='javascript'>alert('登陆失败');</script>");
}
}

为什么老是提示超时？怎么解决啊？？

没人吊?

Response.Write("<script language='javascript'>alert('登陆成功');window.location.href= 'Admin_index.aspx';</script>");