Can't put Music on my Iphone 4S

Okay so I had to get my computer wiped because of a virus infected it and I Got it back today. And I wanted to put some new music on my Iphone. So I got Itunes but when I opened it up did not have the same Library I did not mind that. But when I went to put music on my Iphone then it would not go in. I tried checking"Manually Manage Music and Video" but when I pressed apply I got a message saying "An Iphone can be synced with only one Itunes library at a time. Erasing and syncing replaces the contents of this Iphone with the contents of this iTunes Library".

What do I do help thanks

Oh man, this is a harsh situation. I believe the only way is to erase and sync your iPhone with the new library. It won't erase all your settings or anything, just all your media. (Apps, Videos, Music, etc.). Sorry to hear it man.

Went through the same thing last year but when Itunes library is different then your iphones it says that. Then you would have to erase and sync but if your lazy and don't want to do that then get the songs you want and drag them to to the iphone it helped me while i re downloaded my music onto another Laptop.