Can you still connect your iphone if taken apart?

Ok so i took the screen and lcd screen off my 3gs cause it cracked and broke then i got an iphone 4 but i want to get some stuff off my 3gs everything is still intact but the screens can i still connect it to itunes and get everything back or do i have to put it back together please someone help me very important thank you for your help

Added (1). It is just the screens nothing else i connect it to he computer but it hasn't been on in a long time so think its charging to turn on but i don't now i may put the screens back in to see if it turns on or not

That depends on how far taken apart the old phone is. You can try to connect as-is to determine if it will work for connecting to your computer. If it does, you are set, if not, the phone needs to be repaired before you can retrieve anything on it.