Welcome to MacRumors,
redbusa06.
It sounds like your iPhone is currently synced with another computer (ie a different iTunes library), is this correct?
The iPhone is designed to mirror the iTunes library with which it is synced. In other words, it's your portable iTunes library away from your computer; if you add or delete songs on your computer, the same songs will be added/deleted from your iPhone upon the next sync.
Assuming I understand the situation correctly, your issue stems from the fact that your ringtones are not in the same iTunes library as the music on your iPhone.
Do you still have access to the computer to which your iPhone was originally synced? If so, then your ringtones can simply be added to that computer and be synced regularly. If that isn't possible, then the next-best option is to add all of your music to your new (ie current) computer, and then sync. The music on your iPhone will be deleted, but will be replaced by the music on your computer. Assuming you are able to add all of the music to your computer (from a backup, for example, or CDs), then you should be fine.
Let us know if you have any problems, or if I haven't understood the situation correctly.