Uncheck checkboxes on a subform

I am a beginner with access database. I am building a database for supplies. I have a form with a subform query. The query has checkboxes on it. When the user selects the checkbox they are choosing what supplies they need. They will press a request command button which will open a confirmation window that displays the items they chose (another query). I would like for when they press the request button that the checkboxes clear on the subform query. I have tried several different ways of coding this with no luck. I don't know SQL very well and have been trying to do everything with VBA in the event codes. Can anyone help me out and point me in the right direction.