If this is a listbox on a form, you'd use the click or double click event of the listbox to open a form to the record you wish to display. If you're coding, the click even is listed on the Event tab of the property sheet (when the listbox is the selected control in design view). The ellipses button on the line for the even will open the code window. Personally I'd use the double click event, not the click event.
Not hard to do what you need, but it seems that you don't have the basics yet, so try this site or find one you like better.
https://social.msdn.microsoft.com/Fo...orum=accessdev
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.