cross posting/accessing direct url

HI,

I am developing an application in MVC .

I want that no one could cross posting (means unauthorized person can give the direct url and open the application ).

I want to use something like antiforgery or some better light weight solution .I don't want to write a Custom Filter.

I want to use something primitive feature and I don't want to use identity (memebership api) .

I am using mysql