If column A =" X " then print Column B = " Y"

Hello,

I would like to know macro for this

If column A = "Hello" then print Column B = number 0
If column A = "Hi" then print Column B = Number 7
If column A = "Good" then print Column B = "Morning"


I have 1000+ rows, so i would like to have macro instead of formula for these three cases in one macro.
And i have 10+ worksheet and i need this on "Worksheet 5" only.

sorry, it doesn't work..