rf problem

[-Dan-]

HI

i'm using the

AM-RT4-433 - 433mhz Am transmitter module and the
AM-HRR3-433 - 433mhz am receiver

i am experimenting with sending data wirelessly from one pic to another,
but i do not receive anything on the receive end when using these am modules.

serout2 portb.1,n2400,[$55,$55,$60,transmit_data]

serin2 portb.0,n2400,[wait($60),data_received]

above are extract's from my transmit and receive code, there how i'm transmitting and receiving, this works via a wire link but not with these modules?

am i missing something, do i have to change anything if my data is being sent wirelessly

Thanks.