"How to make Auto log out"

hi friends

i have created one  page and there is one logout button, i have written the code for log out is

//Code For Logout of User
clsAdminUsers obAdmin = new clsAdminUsers(Request.PhysicalApplicationPath);
obAdmin._UserId = lblID.InnerText;

Application.Lock();
bool blnResult = obAdmin.LogoutUser();
Application.UnLock();
if (blnResult)
{
Response.Redirect("AdminLogout.aspx"); Go to the complete details ...