I'm using Crystal Reports 8.5 and also have Crystal Reports 2011, but am using 8.5 in this case.  This issue always perplexes me.  I have about 6717 records which I'm reporting on.  One field in all these records is sometimes null when it should have a value.  I can't make it required, so I'd like to create a report which allows me to list only the entries where no value was entered, that is to say a null value.  In SelectExport I can select the field (it's named Files.Custom13 and is a text field) and I have created formulas before so I'd like to create a formula which allows the Select Expert to produce only results where the field's value is null.  I have one other select expert condition so the statement to return only the records where Custom13 is null will be after the operator "and" Here's what the part before "and" states:

Comatt1,

make sure your CR options, dont convert nulls to default values, in your main report settings