I've got a searh form with about 8 different boxes where a user can enter data to search from. To save writing many different search commands I want to be able to write one and if the field is empty then search all records

for example

SELECT * FROM MyTable WHERE CarType = CarType.Text And Color = Color.Text

If a user enters a Color then search it otherwise don't narrow down the results so like this

SELECT * FROM MyTable WHERE CarType = ""

How can I do this? would it be like the % sine if Color.Text is = String.Empty??