I can't connect my Xbox 360 Slim to the Surround Sound?

-I've been trying to connect my Xbox 360 Slim to my surround sound system for a long time now, and I just can not get it to work! On the Xbox website it says to plug the HDMI cable into the TV for video, and then connect one end of the digital audio cable to the Xbox, and the other to the receiver. I do this, and the sound is still only coming from the TV. I've tried changing a million settings on the receiver itself, but I still can't get it to work! Any help?What type of surround sound do you have, is it a receiver or one of them home theater in a box. Home theater in a box are not very flexible in adding anything to it and normally will only have an optical audio input if any. those bargain price home theater some time only have an rca jack for stereo input at most. If you have your XBOX connected to the tv via HDMI, the you need to connect an optical audio from the tv to the home theater or receiver to have sound. If you have a receiver you can connect the XBOX directly to the receiver using HDMI cable and then connect the receiver to the tv using HDMI cable. Keep in mind if you use HDMI cable that you set your XBOX to output the video and audio via HDMI cable. Receiver usually will have at less two set of input for the optical audio. Hope this will help you out.