How do you activate ILS in flight simulator x?

I know how to land in ILS, but I don't know how to activate it. I check the charts, and I know the runway ILS frequencies. But I don't know where to dial the frequency. I try entering the frequency in the ADF, but i only get the distance from the runway. When I enter it in the NAV Radio, I only hear the beeping sounds. I can't activate the ILS lines in the PFD. I fly the 737-800. Thanks!