no sound from earphones when plugged in

Hey,

I have just bought some new earphones but when i plug them in to my laptop
there is no sound. i know the earphopnes work becaus ei have tested them else
where, i also know that the earphone port works on my comp because i have
tested the device and they test jingle is heard.
however when playing music through windows media player the sound works fine
through the normal speaks but when you connect the earphones the speakers
stop but no music from the earphones.I was wondering if anyone had any ideas
on my problem.


Thanks