Newbie - so forgive me if this is an easy question to answer. I have a table that has a Project number field for identifying each of our projects (Example 1601, 1602 etc) that get assigned as we acquire a project. I would like to create another field that uses the project number as part of its value and builds sequentially each time I enter a record for that project. For example Contract# 1601-001, 1601-0002. The next time I go to enter a new contract I select the project and then the contract # field knows that 1601-003 should be the next number. How do you write that formula?