NULL Values in Indexes - Confused

We have a table with 1.2 million records which is regularly queried to see whether a date field is NULL. I understand that NULL values are not stored in indexes, so if I created an index on this date field, would it be used in the query? Approx. 10% of the data contains a NULL date field.

Dipen Received on Thu Aug 12 1999 - 08:01:20 CDT