ok so this is for those who are following a guide or something to lvl enchanting and need to enchant something over and over.
1. click enchant
2. click the item
3. click ok when it says would u like to replace ____ with _____
4. while casting repeat steps 1 and 2
5. when the cast is almost done click ok to replace
normally it clloses this box if you let the cast finish.
random tip but saves a few seconds