Max value from differents fields (Access table)

Hi,
Is their any function where I can have the maximum between differents fields ?
Example:

Table:
tb_Sales

Fields:
Jan_Sales = 2000
Feb_Sales= 3000
Mar_Sales=2000

In a query, is their a function like
Max(Jan_Sales,Feb_Sales, Mar_Sales)
that  will give me 3000

thanks