You got to use dynamic sql then. construct the sql statement that takes the field parameter and then use EXEC function to execute that.
Code:
Create proc ProcName (@FIELDNAME varchar(100))
as
Declare @strSql varchar(100)
@strSql = "Select * from tablename where @FIELDNAME is NULL"
Exec(@strSql)
Hope that helps.
Cheers!
_________________________
- Vijay G
Strive for Perfection