my xbox 360 game doesnt come in full screen

i have got lost planet on 360 and it doesnt come in full screen it has black strips at the top and bottom, and i dont have a hd tv its

standard crt any way to make it come in full screen

thanks 

Have you tried changing the display settings on the XBOX 360 dashboard?jhz

no i havnt i got my 360 just a few days ago..but is there a setting were you can do that? i mean change it to full resolution