Calculate unless blank

[Raisedwell]

Currently if the date of 2/16/2010 is entered into cell N4, my formula will take the date (mmddyyyy) and display in it's resident cell as 2010-Q1.

My formula:
=YEAR(N4)&"-Q"&INT((MONTH(N4)+2)/3)

Question:
What formula could I use that said, if blank, do nothing. If date, then my formula?

Any help is greatly appreciated.

[zbor]

Try =IF(A1="","",formula)