Say "It's a pleasure to help." Or "You're welcome."
You are welcome or abbreviated you're welcome
Thank you for your correction is the correct way to use your proper English. You are welcome for my correction.
To acknowledge your appreciation 177
Look the person in the eye and say, "Thank you!"
Art of the Thank-You Note
Top 5: Tech to be Thankful for
Working with Wikipedia 101 - #10 - Digging Deeper in Wikipedia
Sending Thank-You Notes Etiquette by Email After a Job Interview