Forms Authentication in web.config

hi
i have a problem with forms authentication
i have a website and want to restrict access to an especific folder
i want the access to this folder be made via the login form
this is what i have in the web.config
<authentication mode="Forms">
    <forms name="Compra" loginUrl="wfLogin.aspx" path="/" protection="All" timeout="30" />
</authentication>
<authorization>
    <allow users="*"/>
</authorization>
Then this to restrict folder
<location path="Admin">
    <system.web>
        <authorization>
            <deny users="*"/>
        </authorization>
  & ...