intel dp43tf front panel audio connected but no sound

today i got a stereo headphones with a stereo mini plug, but i had to connect the front panel audio to my asus vento 7700 pc case, i checked intel's manual for my mobo and connected the front panel audio to where they said to on the mobo but when i plugged in the headphones i get no audio but i checked them earlier on my laptop and they work great.
the front audio cable is keyed and i have it plugged in the only way you can.
to let you know i'm running windows vista home premium, could i have to turn on a setting??

http://downloadmirror.intel.com/15994/eng/DP43TF_ProductGuide01_English.pdf

 

never mind i got it working:-D
http://www.rm.com/Support/TechnicalArticle.asp?cref=TEC949416