Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
when i put a sword into an enchanting table it generated a set of three possible enchantments and i expected it to generate a new set each time.
What actually happened was...:
upon taking it out and putting it back in i found that the only way to get a new set of enchantments was to take the sword and enchant it. putting another sword in and destroying the table both had no effect.

Steps to Reproduce:
1. put a sword in an enchantment table
2. view the three single view enchantments shown
3. remove the sword
4. put it back in
5. look at the enchantments
6. repeat steps 1-5 until you are convinced that the enchantments don't change