Check For Not Null In Either Of Two Columns

Content table

deleteddate revokeddate
1/1/2001 null
null 2/2/2003
4/5/2004 null

I am trying to create a stored procedure where.I need to loop through every row of the table and check if there exists a date in either of the column. If date exists in either of the column for every row, I need to update some other stuff.For the above table, it meets my requirement, so I need to update. However if the table is as below, it doesn't meet the requirement, so I don't need to update

deleteddate revokeddate
1/1/2001 null
null null
4/5/2004 null

I started off as below, But I am getting incorrect values.

Declare @deleterevoke bit
Declare @DelRevId int
Declare @DelRevnumrows int
Declare @tempDeletedDate datetime
Declare @tempRevokedDate datetime

[code]....