[CentOS] Where is the kernel source code???

I have centOS 4 installed on my machine but some how it does not support my TV capture card (bt878) in the kernel, so i want to recompile the kernel to add support for my device. However, i cant find centOS 4 kernel source code. I have read some messages in the mailing list and someone said that i just need to yum install kernel-sourcecode to get the source code, i did it but i yum reported that there is no package matched. Please help ________________________________________________________________________ Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.