In Access, the DLookup function returns a value from a specified set of records (or domain).
The syntax for the DLookup function is:
DLookup ( expression, domain, [criteria] )
expression is a field, calculation, control on a form, or function that you wish to return.
domain is the set of records. This can be a table or a query name.
criteria is optional. It is the WHERE clause to apply to the domain.