my iphone was originally set to where i updated and stuff from my desktop, then i got a macbook and somehow switched it to where i update with the laptop. when i switched it to the laptop, it erased everything (apps, songs etc) that i had added from the desktop. i want a bunch of this stuff back on my iphone and i cant put it back on through the desktop. when i plug it in, it will come up in the sidebar but i cant drag any playlists into it. anybody know how to set it up where i can add songs and stuff from both comps? thanks