What type of screen replacement do i need for my iphone 4?

-I have an iphone 4 through Verizon, and i have dropped it twice, cracking it in several places. It hasn't affected the touch screen ability or caused picture discoloration, there are just a few lines going across the screen. What pieces do i need to order to fix it? I know the iphone 4 is made up of an LCD screen, digitizers, and glass. Do i really need to replace all of those parts? Or maybe just the glass.

Thanks guys,All those parts are originally stuck together. Its practically impossible to seperate them. To get it and the tools you need it would cost around 80$. Theres also a chance that you mess up and your iphone will be screwed forever. Your best bet is to take it into a specialty store in your area to have the proffesionals fix it.