SQL view: how to use <= in case construction 1

[fmientjes]

In a view I want to get an amount when the month is less than or equal to 3 (march).
The following code is not accepted, but I don't know why:

CASE MONTH(dbo.gbkmut.date) WHEN <=3 THEN amount ELSE 0 END AS 'YTD_03_Mar'

If I change it to "WHEN 3" it works, but only for March.
Can someone give me a hint over how to achieve the amount when the month is less than or equal to March?

Thanks,
Frans

 

[vongrunt]

Move MONTH(dbo.gbkmut.date) after WHEN

 

[fmientjes]

Thanks vongrunt,
That was my missing link.