I have a query where a user can enter up to three parameters(search conditions), but the user may not enter all three every time they query is called, but they will have to enter at least one of the parameters. For example, I have a query that selects from a table based on a contract number, invoice number, and transaction number. The user can has to enter the invoice number, but the other two are optional(for purposes of narrowing the data returned).
My question is how do I set my query up to run and ignore(??) the parameters that are not required to be entered?// I hope I have made sense with my question.

Thanks in advance for your help