song?

what is the name of the instrumental song that they always play for Kritika and Karan?

http://www.youtube.com/watch?v=QVtdxtvJpco&feature=related

i know the song but i forgot the namee

ITS THE SONG OF MOHABATEIN
I THINK ITS CHALTE CHALTE
OR CHECK THIS PLEEEASE 😃 😃
http://www.youtube.com/watch?v=nW7OhIEd_Wo