tabcontrol+media element

Question

hi
im working with 3.5 wpf window application,c#
i have tabctl wit 3 tabitems(tab1,tab2,tab3).
i have media element in tab2.

i have source uri in a table as 5th column(hosanna.mp3)..on selecting the corresponding row the media element should play(hosanna.mp3)..

when i select tab2 i need to play song when change the change it shud not played..

how to that...
regarda
jai