Can't manually manage music on my iPhone 5

Every time I connect my iPhone 5 to my computer I have to check the box that says "Manually manage music and videos". I save the changes every time, but when I go to plug it into another computer, the box is unchecked and I have to re-sync my iPhone and delete all the music from the previous sync. Is there any way to avoid this do I can have all of the music from multiple computers?

You have to read the manual you got