how get value of records from a query in form UI designer?

how to access the value of records from a query? suppose I have the attributes in BDM are name, access code, age. Then i make form in UI designer that contains of a input widget an access code, and submit button that connects to the form that contains the name and age appropriate data access code is entered. The question is, how do I write code in the input widget and submit button so that I can generate the appropriate data based on the access code?

i use bonita 7.3. Thanks