how to establish rf communication btw two arduino boards\

i tried wat u hav told....i downloaded virtual wire...added it to library....connected tx and rx of hr-1001 to digital i/o pins 11 and 12 of arduinoand gnd and 5v supply was also connected.......and loaded an example code...still itz not wrking.......wat may b the problem....can anyone help me wid this.....