Adding Labels

I used to add labels to all my posts, but I have a problem. Say I put sewing and knitting in one post. In the label box, I put "Sewing; Knitting". It shows on the posts as being ONE label, not two. In the example on the create posts page, it does show separating them with a , so I tried that and it changed the label to something I didn't want. How do I put two separate labels on a post?