Hiding a formula total when there isn't an input

[Berthabel2]

Hi...I'm desperate! I need help with a spreadsheet.

On the spreadsheet (which is a year to date)
Month Bonus Shortage Payable
Jan $500 $300 $200
Feb $000 $300 $000
Mar $000 $300 $000
April $000 $300 $000
and so on

I want to hide the $300 amount (I know the amount will change once I put information in the February cell, but then the march-Dec will change to that amount as well until I input the full year.