multiple conditions on "if" request

multiple conditions on "if" request

I want customers to be able to enter a field to identify them on my web site with the application embedded, but I cannot use the "or" function (see below). It is accepted, but will not work.
 
if ((input.Buyer_ID  !=  12346)  ||  (input.Buyer_ID  !=  12345))
{
    alert "If you are not registered, you cannot bid. Please go to www.xxx.co.uk to register";
    cancel submit;
}




Can you advise please how I can do this?
 
Kind regards
 
dp