NULL And MAX Query

Hi

I have a table called Orders with columns OrderId, ItemReceiptDate and itemnumber.

Sample Data is given below:

OrderID | ItemReceiptDate | ItemNumber
-------------------------------------------
1 | '2004-01-01' | 3
1 | '2004-01-28' | 4
1 | NULL | 5
2 | '2002-11-19' | 1
2 | '2003-01-28' | 4


What I would like to SELECT is:

OrderID | ItemReceiptDate | ItemNumber
-------------------------------------------
1 | NULL | 5

2 | '2003-01-28' | 4


i.e. if ItemReceiptDate is null for a particular order id ==> return that record
else return the record with maximum ItemReceiptDate.

Please help.

Thanks