lounge light?

hi i am change my lights in lounge their 4 red 4 black and 4 earth-one off the black wires is a live wire which i connect to the live one the light flex-have put the rest black wires to gether and the 4 reds in another point on the earth etc---however when i trun light on the swich dont work??-and the othert light in the same room not come as do not any other light on the ground floor work at mo i would be gratefull for any help ith where i am goin wrong i no this is on a loop can anyone tell me what wires go where cheers