call ringtone

hi guys,
i recently got a blackberrry and the issue is is that
whenever someone calls the phone ring normally but if accidentally touch the screen ,
rings goes silent (even vibration stops) And the problem is that when my phone is in my pocket{jeans} and calls come, caller screen got touched accidentlly(somehow) inside my pocket....
and thus i could;nt get notified 4 call(bcoz its goes silent nd don't even vibrate).
I KNOW THIS IN NOT BLACKBERRY ISSUE , BUT IS THERE ANY SETTING FOR IT

THANK YOU FRIENDS!
new bb user(2BC8FEDC)

That is by design.

I suggest you get a pocket pouch: ShopCrackBerry - #1 Store for BlackBerry Accessories